1861-2.

V [CTORIA.

SECOND REPORT

01" THE

BOARD OF VISITORS TO THE OBSERVATORIES;

WITH THE

SECOND AND THIRD ANNUAL REPORTS

OF THE

l}Hl~fmNTED TO BOTH HOUSES OF PARLIAMENT BY HIS EXCELLENCY'S COMMAND .

• 15)! 3utbot:ltl: •

JOHN 1"ERRES, GOVERN~{ENT PRINTER, MELBOURNE. N.c>,121'.

•

·' R E P-ORT OF TWiI

To His Excellency SIR HENRY BARKLY, Knight Oommander.. of the Most

Honorable Order of the Bath, Oaptain-Generdl'andGovernor-in-Ohief"o/

the Oolony of Victoria, and Viee;..Admiral of the 'same, &:~., &:e., dbe.

MAY IT PLEASE YOUR EXCELLENCY,

. In the First Report of the Board. of Visitors, the nature of the work done at the .Astronomical Observatory at Williamstown, and at the Magnetical and, Meteorological Observatory at the Flagstaff Hill, was ftilly .stated" and the, position and instrumental appliances of those establishments were described.

It was then stated-'

, . That the, position of the Astronomical Observatory at Williamstown is altogether unsuitable, from its being in the midst of houses, which greatly limit the horizon, and cause serious irregularities in atmospheric refraction jand from its being also in qlose proximity to the railway, which deranges. the adjustments of the instruments: .' Thatthe Flagstaff Hill is unsuitable. as a site for a Magnetical Observatory, :from the frequent changes in large masses of iron in its immediate neighborhood:

An~ .that.3; site for a new Observatory, for. both purposes>, had been tempo­rarily reserved on the Gov.ernment Domain, near to the Botanical Gardens ..

Since the datI? of that report there have been erected on the new site two detached rooms of wood-one for absolutl.;: deterininationsof the magnetic elements, and the' other for observing their hourly variations.' .

There has also been erected a transit room C!f brick, with the requisite piers for mounting the transit circle. This room forms a part of the plan for the Astronomical Observatory, which will comprise in tJ,dditiOli a pnme vertical room, calcul;1ting room, ,chronometer room, me~eorological room, library, and workshop. It has, however, been found impossible, in the present incomplete state of the buildings, to carry on any of the work of the Observatory at the new site, and consequently none. of the instruments have been removed there.

Since presenting the last report, the Board has twice visited the ObserVatory at Williamstown, and inspected the state of the instruments and the arrangements for ~ar.rying on ·the work. .

The reports of the Government Astronomer presented on those occasions, which are appended to this report, contain a full account of the additions to the instruments in use at the Observatory, the staff employed there, the work on which they have been engaged, and ,the arrangements in connection with the electric telegraph for transmitting time signals to differellt parts of the colony.

The work of the Magnetical and Meteorological Observatory has been carried on regularly at the Flagstaff liilJ, it having been found impossible to commence any regular

, series at the new,site, in consequence' of the unfinished state of the buildings. Owing to 'the absence of Professor Neumayer, who is engaged in the magnetic

survey of the colony, the Board has rec~ived no formal report from liim for the past year. While bearing testimony to the zeal and skill with which the work of the two

Observatories has been carried on by the ,gentlemen in charge of them, so far as the means at their disposal will permit, the Board desires to urge ,upon your Excellency the import­ance of speedily completing the new building ,for ,the Astronomical Observatory.

The Government Astronomer states in his report that-

" The general work of the establishmC'nt has been seriously interrupted by the constant , disturbance emanating from the railway, which, as the Board is aware, is in too great proximity

to the Observatory. The, traffic, has' been and is daily increasing, giving riso to ,an almost uQremitting alteration 'of the adj~stmeilts of the,iti~trUlnents. 'rhe n'ew fortifications, in which will'- be mounted some very heavy 'guns, are now, nearly completed, and· I 'look forward with dread to. ~he ti:rne when these are brought into use for drill and,target practic!'l. I haye good reason to'fear that the disturbance from this source will be almost fatal to the' adjustments of' our 'instruments."

", With respect to the new building in the Gove'rnment Do~ain, 'the transit room' alone has been built. Exeavations, &c., for the .remainder of the building, have also been mado.

, With the tnin~it room alon:e it'wouid b~ impossible to undertake the wor~ of the Ob,senratol'Y on the new site, and I am anxiously awaiting the completion of the building to move from what is; in nearly ev~ry 'respect, a~most ~nsuitable 'and e~en dangerous place for the valuable instruments in my charge."

To these remarks the Board feels that it is unnecessary to add anything, except the . expression 'of opinion, 'from ,. actual inspection, that they 'are in every ;espect borne out

bY' fact. There 'is also another ground for speedily completing the new Observatory. At

-present 'there are two' establishments under distinct management; on removal to the new site these two can be combined, and a considerable reduction effected in the 'annual cost. Many of the 'observations are now necessarily taken in 'duplicate' at the two Observatories, and in many, oth~r paHiculars the 'work in each establishnient is as great as it will be in

, the two combined. '. On: the' ground, therefore, of economy, the Board strongly recommends that· there should be: as little delay ~s possible in carrying on the building for the new Observatory,

. The observations taken at the Astronomical Observatory during the past .two years have been reduced, and the results. are. now ready' for printing. It is desir;:tble that this should be done at once, as it is obviously useless to carryon scientific work at a considerable

'. expense, itilless the results of that w.ork are made public, As it is proposed that the results only should be published, ,and not the observations in full, the 'cost will not be great.

As regards the magnetical and meteorologica,l observations, in consequence of the . absence of Professor N eumayel', the' Board is unable to state at present how far they are ready for publication. The Board has, 'for some time past, been in communication with Professor Neumayer on this.subject (a committee having,been appointed to conferwi.th him), and expects to be able to make a special report in a short time. '

HENRY BARKL Y, ' , , Ohairman.

W. P.·WILSON, Secretary.

ASTRONOMICAL OBSERVATORY, VICTORIA.

SECOND ANNUAL'REPORT TO 'l'HE BOARD OF VISITORS.

SINCE the date of my last' report, great improvements have taken place in the affairs of the Observatory, and I am happy in being able. to render a much more satisfactory account than at the former visitation.

These improvements are in a great measure traceable to the efforts of the Board, more especially as regards the appointment of an assistant, and improvements and additions to the building; which, combin,ed with the acquisition of several new and valuable instruments, has rendered the establishment so much more effective, that I have been enabled not only to get both the ordinary work and the increasing astronomical duties in connection with the geodetic survey performed in a manner highly satisfactory, but also the observations undertaken in connection with other Observatories creditably accomplished; and I feel sure it will be gratifying to the Board to know that our labors are now so far recognized by the older established Obser­vatories of Europe and' America as to have their regular place in most of the astronomical periodicals of the day.

Personal Establishment,-In my previous report to the Board, I urged the necessity of giving me paid and permanent assistance. Shortly afterwards, Mr. E. J. White was appointed as assistant; and it gives me great satisfaction to state, that I believe a gentleman better fitted for the post could not be selected.'

The personal establishment now consists of the astronomer, assistant astronomer, and messenger. On the astronomer, who. also superintends the geodetic survey, devolves the general superintendence, correspondence, &c., and, as fitr as possible, a share of the observing apd computing.

The assistant takes charge of the transit observations and reductions, including deter­minations of clock errors, and the regulation of the time signals, &c.; these form a large portion of the regular duties of the Observatory.

The young man filling the post of messenger might in reality be termed a junior assistant; his duties consist principally in making meteorolog~caLobservations, assisting in computing, care of the galvanic batteries of the electric train of the observatory, reading off the observations from the chronograph, and generally assisting in the regular work of the establishment.

Buildings, o/c.-A short time subsequent to the last visit of the Board, a new room was erected on the west side of the building for the reception of the transit circle, which was then expected to arrive very shortly. The room is 16 feet by 17 feet, and its position, with regard to the older building, as well as the arrangement of the piers, &c" will be seen by reference to accompanying diagram.

By the erection of this room, a large portion of the south opening of the old transit room was closed, and I deemed it necessary to place the transit instrument temporarily on the piers erected for the circle, so as still to have as full a sweep of the meridian as hitherto; and although everything is prepared for the transit circle, it is intended to keep the old transit in this position till the arrival of the former. The chronographic apparatus is also in the room.

. With regard to the foundations and piers for the circle, I am sorry to find they are not so steady as could be desired, there still being slight movements both in azimuth and level, although it is now eight months since they were erected; nevertheless, during the last two months, they have exhibited an increasing stability. This unsteadiness, .I believe is not so much the result or­any defe~tive building, as the fact that the foundations rest on clay, which, although hard and compact, lS scarcely fitted for the foundations of astronomical instruments. The foundations of the ~r.ime vertical ,instrument gave way to so large an extent that I was compelled to have them­lIfted and rebUIlt, but even yet they do not preserve that stability I could wish owing entirely I believe to the clayey subsoil. '

. In the old transit room two brick piers have been built on the original foundation to carry the zenith sector, which arrived some months ago.

A small room, used as a workshop, has also been added to the building. Instruments.-~~er~ have been several new instruments added to the Observatory si nce

the d~te of the, last vlSltatl()ll of the lioard-they are a zenith sector (on Mr. Airy's plan, by ~l'. SImms); a SIdereal clock; by :NIl'. C. ~rodsham; and the chronographic apparatus by Messrs. Sleman~,and H~lske, of Berlm. ~hese ~nstr~ments are ready for the inspection of the Boartl.

I?e zemth s~ctor ,was recClved lD February last. I had it erected immediately in the old il'~nslt roo~, -;hlC11, Sll1ce ,the, re.moval of the transit instrument, had b,een prepared for its receptIOn, ThIS 1l1st\'ument lS slmllar' to one first made for the Ordnance Survey of Great

No. 126, a.

6

Britain, and as its peculiar construction is now well known under the name of Airy's Zenith Sector, it will not be necessary for me to describe it, or the mode of using it here; but when it is under the inspection of the Board, I shall be happy orally to explain its construction and use.

The new sidereal clock arrived· in October last, and reached us in excellent order. It was placed in the prime vertical room, where a pier had been prepared for it. This clock has the usual Gl"fLham's dead beat escapement and mercurial pendulum, with Dent's iron cistern. It is a fine specimen of the m!.ker's well-known superior workmanship.

The prime vertical instrument, which is intended for. field usc, arrived last December. Its only peculiarity is, 'that it has It telescope in'the axis, to facilitate its being set at right angles to the meridian-a matter of great importance in the geodetic survey. It has also two setting circles, divided on the edges. This instrument is temporarily erected in the Observatory, and will shortly he required in the field. .

The chronographic apparatus was received in October last, and was at ouce erected; ever since which'it has been in admirable working order, and has proved itself to be a most excellent instrument, and. does much credit to the makers, Messrs. Siemans and Halske.

The apparatus consists of a double system of recording magnets, with clock-work for carrying the paper fillet; a double electro magnet, for stopping and starting, by means of the

·'electric current; a galvanometer, portable key, and magnetic clock-contact apparatus. , The regulation of the clock train, which keeps the paper fillet in motion, is by means of

a very effective, but simple governor, a modification of Froude's By-the driving weight being wound up by means of an endless chain. The recording styles are perforating points, which are made by means ot delicate springs to follow the motion of the fillet, so that a fine puncture is made exactly on the instant of first contact, the point being immediately prevented from a.brading the paper by its yielding, in the direction of its motion. Wires lead from this appa­ratus to both the sidereal clocks. and to the electric motor clock. Three wires are also led to the piers of the transit instrument, two of them terminating in two contact springs, so placed that one is always within conv:enient reach of the observer's hand, in whatever position he may be at the instrument; and a third contact spring, capable of joining the first and third of these wires, serves to' stop the mechanism of the chronograph by mcans of the extra pair of electro magnets.

The chronograph can also be readily connected with the telegraph lines of the colony by wires leading into the operating room of the adjoining station, from which place it is also con­nected with wires leading to the time-ball room of the lighthouse tower. The different circuits a.re so arranged that by means of switches they can at once be interrupted to prevent waste of battery power, or turned to flow in any direction required; thus, either of the two clocks can be made to record their beats on the paper fillet, or both clocks can be simultaneously placed in circuit, and so made to compare themselves.

Clock-beats or observation signals can be transmitted from it, along the telegraph wires, , to any station included in their circuit, or conversely received directly on the recording fillet.

By meaus of a telegraph rope (a line with a silk covered wire wormed in each stra:1d), a portable key is cOllnected with the apparatus; this can be led to any part of the building or premises, and is very useful for occasional ob!3crvations and comparisons. The ciI:cuits .are worked with Daniell's battery, two cells being generitJly used to each.

The clock contacts are made through the agency of a special apparatus; one the escape wheel arbor of each clock, an extra wheel with sixty conical teeth is applied, a pair of delicate springs insulated from each other, and from the clock works, are so arranged that they are brought into contact every second by the cOllical teeth of the extra wheel; one tooth of this wheel is cut out and corresponds to the sixtieth second, by this means a beat is left out on the fillet paper every minute, which serves as a dale' in reading off'. This arrangement is very similar to that adopted at Greenwich, and acts very satisfactorily. The eonical teeth of the extra wheel merely !lcting on the springs in passing, the only effect it has on the tmin is to take off' a slight portion of the action of the weight, and in a very small degree lessen the impulse; but this has no appreciable effect on the performance of the clock.

Some short time ago, the old sidereal clock evinced It great unsteadiness in its rate, which could not be traced altogether to wllnt of compensation: After some watching and experiment, I came to the conclusion that it was the result of some undue resistance offered by the contact springs, and had a small tilt !tammer' contact apparatus applied to replace the original springs; but I then found that the springs had been applied badly, as they were acted on before the line of centres, and the paUet of the spring was met by the conical teeth at a bad angle. The tilt !tammer certainly relieved the clock in a great measure, bnt its inconvenience' in breaking circuit each beat instea,l of making 'it, and the fact that I had discovered quite sufficient cause to account for its bad performance in the old position of the springs, has induced me to re-apply them in a proper manner. ....

The transit instrument by Troughton and Simms, descrIbed III my-lastreport, and wlth which al1-the observations in R. A, are still made, continues to give every satisfaction. The object-<rlass I consider unusually good of its size: stars of the fifth and even the sixth magnitude have b~en frequently and successfully observe~ with it ~n broad da!li~ht. .

It is, as I have before stated, temporarily fixed m the transIt CIrcle piers. The other instruments, as detailed in my former report, remain the same as at that date,

with the exception of the original chronographic apparatus, which has been sent to the Sydney Observatory.

In July last year, a zenith sector or micrometer of Capt. Kater's construction was lent

7

to us by the Sydney Government; this was erected in a small room erected for the purpose, but since the arrival of the new sector it has not been used, und it will in a short time be returned.

The time ball was removed from its original position on the telegraph tower to the lighthouse tower in last. This change has given great ~atisfaction, especially to the maritime community, for hitherto it was visible only to a very limited portion of the Bay, but can now be readily seen from any part of tIle harbor. The ball is dropped every day, Sundays exeepted, at one o'clock, as usual: the exact time of its drop is precisely recorded by means of the chronogl'apll, and any error, which is seldom appreciable, is published in the daily papers.

The tran"it circle, which was expected to arrive as long ago as last Mayor June, I am sorry to say has not yet come to hand, although recent advices inform me or its proposed ship­ment in the Roxburglt Ca,stle, which was to leave London about the 6th April, The principal Clluse of this great delay has arisen from the death of ~fr. Simms, and the fact that Mr. Simms, junior (who succeeds to the business), not being aware of the arrangements made with regard to payment, &c.; but on his al)plying to the Agent General for the Colonies, a short time sub~equent, he became informed, and sent me the above advices.

The prime vertical instrument from Munich llas not yet arrived. I have had intelli­gence of its progress, and it lllay be expected now almost daily.

The Library of the Observatory has had sever,al valuable ndditions made to it since the last visitation. They include the results 'of the Greenwich Observations for 1857 and 1858, presented by the Lords of the Admiralty through the Astronomer Royal. A valuable collection of books llnd pamphlets, being the Annals and Notes of the Brussels Observatory, presented by M. Quetelez. The Radcliffe Catalogue for 1845, presented by the Trustees of the Radcliffe Observatory, Oxford. The Greenwich Twelye-Year and Six-Year Catalogues, and Gould's Astronomical Journal, from the first volume to the present date. The latter works have been purchased by the Government. .

A few months ago I received the following circular from the Astronomer Royal :-

Royal Observatory, Greenwich, DEAR Slll, 20th October, 1860.

With a view of enabling you to complete the set of Greenwich Observations, and other publications of the Royal Observatory, Greenw'ich, in the Library of t,he Observatory of Williamstown, I transmit to you the following general statement of the number of copies OIl hand (a list of the Greenwich Observations and other publications inserted).

If you will have the goodness to communicate to me a list of the volumes required, and if you will indicate the channel by which they will be most conveniently sent, I will endeavour to transmit them with the least possible expense,

I am, dear Sir, Yours faithfully,

To R. L. J. Ellery, Esq. (Signed) G. B. AIRY. "

In reply, I sent the following:-Government Observatory, 'Villiamstown, Victoria,

Sm, 22nd January, 1861. I have the honor to acknowledge the receipt of your circular respecting the Greenwich pUblications

(dated 20th October, 1860), and in reply beg to inform you that, with the exception of the following, none of the list sent are in the Library of the Observatory :- .

$ (Greenwich Twelve-Year Catalogne. +> • I Greenwich Six-Year Catalogue, '48 to '53 . . s t> Bessell's Refractions >, l"l ~ Description of Reflex Zenith Tube. ~ ~ I Fallow's Observations. 1: Greenwich Results of Astronomical, ~!agnet\eal, n.nd Meteorological Observations, for < l the Years 1848, '49, '50, '51, '52, '53, '54, '55, '56, '57, and 1858.

The following, from the list sent by you, would be found most useful additions to our Library:­Bradley and Maskelyne's Observations, Greenwich Observations, Reports to Boards of Visitors, Reductions of Planet Observations, Reductions of Moon Observations, Hansen's" Tables de la Lune:'

With regard to the channel of transmission, any of the" Blackwall" line of ships bound to Melbourne would deliver the books, or, if more convenient, Messrs, Simms would despatch them.

I hn.ve tIle honor to be, Your most obedient Servant,

(Signed) ROBERT L. J. ELLERY, To the Astronomer Royal, Government Astronomer, &c.

Greenwich.

The intimate connection necessarily existing between the Observatory and the geodetic survey has, in a very great measure, influenced the direction of our labors; and, indeed, the o?servations made in connection with it, form by far the largest portion of the regular work of the establishment.

The accurate determination of time for public purposes is, as it ever has been, a matter of primary consideration; and this, with the observations of the Moon and Moon culminating stars, comprize the two most important duties of the Observatory-with the regular performance of which nothing is allowed to interfere.

The want of working star lists for the field observatories has given rise to the necessity

· 8

for < underti+ki~g th!=l ,determinatio~ of the places of a large number of stars selected from the B. A. C. Catalogue up to the sixth magnitude, which either pass witllin the zenith of all 'latitudes in the colony or are circumpolar: this involves a great amOJDt of labor both in obse,rving and reducing. .

, The,determinations of the polar distances are at present necessarily confiped within the ,limits or the zenith sector and prime vertical instruments, which do not ,exceed 12° each side , of the ,zenith of th~ Observatory. '

" , The Moon culminations are observed for comparison with the principal Observatories of Europe and America, for the ultimate determinatiou of our longitude; ana about four times yearly' t4e.,obser.vations are forwar~ed in the forl'\1 oflithographic sheet to Greenwich"Altona, Brussels, Paris" Cape of (l;s)od Hope, Washington, Jrremsmi'nster, Madras, &c., from which places I receiv~ corr~spollding oJ:lserva,tioI) in return. '." . '

J",. : D~ring the past Y'ear, tbefollowing ,numb~r of observations have been made :-

With the transit instrument 3,240 Prime vertical ... 70 Zenith sector 178

, These observations'are all red~ced, the practice being adopted of.reducing them at once. The number of transit observations is about equal to what is obtained at Greenwich. , Very few observations of the sun or planets will be found amongst .the past year's work. :~t ha~ not beel} deemed necessary to take up time with such observations, more especially as the Cape . Observatory, with its higher class of instruments, specially undertakes that particular dl?partment of ol)serving. '. ' , The transit observations for 1860 have been tabulated, and r have now the honor to lay

them before you, as well as copies of all the lithog~'aph sheets of Moon culminations that have been distributed to the several Observatories. '

,', ' In January last, a partial eclipse of the Bun occurred, but owing to the cloudy state of the weather, it could only be observed during its middle phases; but as it the meridiaIl,

"'eclipsed; the limbs' of both sun' arid moon' were' fully observed, with the transit instrument, through a break in the clouds. < '

The comet No. iii., 1860, was first seen at the Observatory on the 10th July; btltI ;'am 'sorry to state that,' with the exception of a set of careful sextant measures by Mr. White, no obse'i-vations could be made, as 'the Observatory possesses no telescope adapted for occasional observations of this kind. This is much to be regretted, for besides the exact determinations for· more purely scientific purposes, which are expected of an establishment like this, the public always :look to the Ooservatory for descriptive accounts of physical appearances in phenomena of this kind, and will scarcely believe that they cannot be afforded for want of a good telescope.

In November next, a transit of :Mercury across the sun's disc will, if the weather permit, be visibl!? here. Although this will not possess near the scientific value of the transit of Venus, it is of somewhat rare: occurrence, and nO pains should be spared to obtain as complete an observation as possible; and I trust that I may be able to secure some good instrument for the purpose. , '

To be prepared, as far as possible, I am having an equatorial mouuting made which will be capable of carrying any telescope that it may fall to mfgood fortune to obtain.

The determination of the difIi3rence' of longitude between this .Observatory, Sydney, ami Adelaide, by means of the electric telegraph, is in con'templation, and I have made the arrangements for connecting'the telegraph lines to the chronographic apparatus as complete':md 'convenient as possible. J'luI.Ve alSo, by the kind aid of S. W. MacGowan, Esq., Superintendent of Electric Telegraphs, made the first of a series of experimentsJor ascertaining the velocity of the electric current 'on the telegraph lines, as'well'as the resistance offered to the current by the magnets, &c., in circuit.

By the first experiment, the velocity was found to be about 14,000 miles a second; but, with the interposition of the ordinary telegraph instruments, only between 4,000 and 5,000 miles a second. I propose, however, repeating the experiment several times, before arriving at any definite conclusion. . . , .

, The principal triangulation of the .colony has now been completed over rather more than 3 degrees'ofIongitude, to tlie eastwar~s; and a point, not farfroni the telegraph office at Hamilton, has been fixed, with respect to the general triangulation, very accurately. I therefore propose, as soon as the time can be spared, to obtain an astronomical measurement of the arC of parallel. This will be a determination of considerable interest and value, if properly made, inasmuch as the elements of the figure of the earth adopted by Colonel James, on the calculations 'of the Ordnance geodetic tables (which are used in our geodetic survey), differ from those'of Airy's and l.3essell's hitherto used, to an amount that will, in the distauce from the Observatory to Hamilton, niake a'differenee of about 110 feet. By the means I propose adopting, a tenth part of this will, I think, be discoverable. ' ,

During the past year, I have Lad to lay before the Board several reports with regard 'to the site for a new. building, combining ~he Astronomical and the Magnetical and Meteorological pbservatories., The sitese~ected and obtainedby theB~ard for the purpose is, I feel cOllyinced, tlie best of any in the vicinity of Melbourne. The several experiments I have made to test its eligibility for" astronomical purpose ha'vebeen satisfactory and conclusive, and I trust the Board will ultimately, su~ceedin, their efforts to obtain a grant for the building. .

ROB. L. J. ELLERY,

May 30th, 1861. Astronomer.

ASTRONOMICAL OBSERVATORY, VICTORIA.

THIRD ANNUAL REPORT TO THE BOARD OF VISITORS.

IN the Report which I have now the honor to lay before the Board of Visitors is comprised the history of the Observatory since the date of the last visitation up to the 21st May, 1862, and applies to the state' of the Observatory at the last named date. .

Personal Establishment.-This remains the same as at the date of my last report. Mr. White, the assistanf astronomer, retains charge of al) reductions of R. A. observations, comparison of clocks, chronometers, and the giving of time signals, in addition to his share of observing. The junior assistant (who last year was merely paid as a messenger) continues the same duties as mentioncd in my last report. There has been a change in the manner in which the establishment appears on the Estimates this year. The" Observatory" is now placed as a separate sub-department, under the Commissioner of Lands and Survey, and includes-

The Astronomer, Assistant Astronomer, Junior Assistant,

With a small amount for contingent expenses, such as lighting, purchase of books, repairs to instruments, &c.

Buildings, o/c.-Since the last visit of the Board, a small equatorial room has been erected in the grounds: it consists of a circular chamber about 10 feet diameter inside, surmounted by a revolving roof of a drum shape. The walls of this room are of brick and cement work; the roof revolves on cannon balls running in channels on the wall-plate, and in the under surface of the roof frame. At present this room is used for a small equatorial which I had made here: it was intended at first fOl: a five feet equatorial I have for some time been expecting from England. The south fence of the ground .has also been moved a few yards farther back in order to enclose the equatorial room. The rest of the buildings are in much the same state ns in last May, the lighthouse still being used as the time-ball tower, the rooms beneath forming storerooms for geodetic apparatus, &c.

Instruments.-In my last report I stated that I was in daily expectation of hearing from Messrs. Troughton and Simms, of the shipment of the transit circle. A short time subsequently, I received bills of lading, and in August it arrived in the ship Maxwell, and was received at the Observatory in good order on the 17th of that month; and the piers having 'been already prepared, it was completely mounted on the 26th, and on the 27th the first observations were made with it. It is a very fine specimen of the Messrs. Simms' well-known workmanship. The plan ~md details of the instrument were entrusted to the Astronomer Royal, and we have every reason to consider it a first-class instrument. It consists of a transit telescope of 6 feet focal length, with an effeetive aperture of 5 inches, and a circle of 4 feet diameter attached to the western cone of the axis. The circle is graduated on silver to every 5 minutes, and is rcad to 1" by means of micrometer microscopes, of which there are four attached to the western pier. The instrument is counterpoised so that there remains but very little weight on the hearings. It is fitten with the proper appliances for the chronographic method of observing, and lor illuminating the wires in either a dark or light field. I have not yet been able to get a satisfactory wMte wire on a dark -field, owing, I believe, to some want of adjustment of the prisms in the cube, which I hope to be able to remedy the next time the instrument can he spared for a thorough adjustment. Fortnnately, this method of illumination has not been much required yet, our observations consisting of such stars as will gencrally bear a moderate' amount of light.

There are two collimating telescopes (one north and one south) for the determination of the error of collimation, similar to those of the Greenwich transit circle; but our instru­ment possesses a great advantage over a great many others of the class in having a perforated cube, so that in order to adjust the collimniors one on another it is not necessary to raise the instrument from its bearings-an operation attended with considerable trouble and risk of dis­turbl~nce. The determination of the error of level and the nadir point is by means of a Bohnenberger's eye-piece, and a quicksilver horizon, which enables the observer to compare the wires with their reflected images, and to measure the space between the two.

The illumination of the wire3 of the instrument, and of the limb of the circle opposite the four microscopes, is all effected by means of one lamp-a series of reflectors, condensers, nnd prisms taking the light to where it is reqnired. I shall be able to describe the instrument more in detail when it is under the inspection of the Board.

No. 126, b.

10

I have made one or two small additions, and, I believe, improvements, to it, suggested by experience, sinqe its first erection :-

1st. To facilitate setting the instrument, I have fixed one of the small setting circles,of the old transit towards the eye end of the tube. This has proved of very great advantage, and a decided improvement.

2nd. I have introduced a set of spider lines between those first fixed on the instrument; these lines have intervals of about 1',4. I was induced to do this inas­much as, by the chronographic method, an interval of l' for a quick moving star was found amply sufficient; and, as much of our work now and hereafter does and will consist of observations of close circumpolar stars, much time is thereby saved, and the chances of losing, or getting defective, observations in cloudy weather much diminished.

The difficulty of obtaining, on some occasions, a good level-error, by means of the Bohnenberger eye-piece, in consequence of tremor caused by trains on the railway, or high winds, and of obtaining any idea of the shape or equality 'of the pivots, induced me to have a spirit­level made which could be readily applied,to.the axis; this level is just completed, but has not 'b!3en used yet. While speaking on this subject, 1 may mention, I experienced great difficulty in obtaining a ~alm surface to the quicksilver, owing to the many causes of disturbance in the neighborhood; but, after several experiments, I.su~ceeded in subduing 'lI;,great. amount of the tr,emor by suspending the mercury ,box in a frame by means of eaoutchouc band8, the frame itself being suspended inside a box in the same wp.y. .' " . ',r, ,,' ',I,'he,z!"nith seetor, which I described in my last repor:t, has 'pr<,!ved .3. good and ~aluabl~ instrument ;, it has been used principally in determining the Z; D. of stars ~or use in the geodetic survey, and' fatterly iIi observations in, connection with the circle for'latitude, &c.

The 1'\mall primc vertical transit, which occupied the prime vertical room at the date of the last visit, was removed for use on the geodetic survey in June last. The great unsteadiness of the foundation on which this instrument r~sted has maile.,me disinclined to mount any other instrument in its pillce, more especially as the zenith sector is capable of doing all the work that coul? be required of a prime vertical transit at present. ., .

I have had a small equatorial, of a temporary description, made to facilitate the observa­tions of occultations, eclipses, &c.; the object-glass is that belonging to the old transit, than »,:hi{,lh, Ifo,ne of its ~i~e,I beli~ve",could be bettl?r. , This instrument nQw,oc~upies the equatorial ,room before mentioned, and has been found very useful in the occasional observations.

. Several improvements have been made in connection with the clocks and the chronographic arrangements ... Both the sidereal clocks. occupy the positions in the Observatory as hitherto. , ... , . The,l~ew one has fully justified,Qur anticipations, and has given every satisfaction; but ,t.l;1e cont:1ct,for, the galvanic, conQHc~ioI}. gave sorl.1e little trpuble, in keeping in adjustment, as I ,~fterw!1rds found in consequel')ce.of badly-made springs; and, ,in August last I had a fresh set of s.prings.and a n~w 60-teeth extra wheel con,structep"the' tcet~ of which being cut much more inclined than in the wheel before used, so that ,tile springs are acted on more gradually, and are J.?J:(P.lg}l~,~nt,obette~· pontll'<:t; i~.ff1et, I {,lopie(l, asriearly as possible, the plan used at Greenwich, which is, shown in a plate acco)llpanying the observations for 1856. Stnce this alteration, no It~oul?le whatever has been e1l\perieneed,with.the clock contact. i'.j".' The old, sidereal clock has been r,nuch more steady in its rate since the application of the ,n~w pendulum ment$Qned in my last report. ~ , , .

, . ~n 'Q.ecember, last, the electri~, motor clock.was dismounted. It was intended that all time signals shoufd .be,giv,en fr?m.this dock,but. cQnstanj;ly recurring irregularities, depending in a ,n;I~rked ,degree on t4e strength of the Rendulum P!l!tteries,indi.cated its unfitness for this purpose. ,I therefore put in its place the old clock ,by Evans, which. wits the first .clock possessed by the :ObservatoI'Y"and had been fQr several years in the Telegraph Office adjoining. In order that ,~his 'clockshoufP. supply, tpe requisitlii:ga\vanic signal~ for time, I had a contact wh.eel put on the :se~onds',arbor, Wi'Fh teeth so plac~d thafa pair of "connecting springs were brought in contact at the 20, 30, 40, .. 50,. and five,concluding, seconds of each minute; arrangement is also made that th!"se signals .can b.e, given eaeh n;I,inute, 01' every. hour only, or that one contact only is made at .the completion ,of each minute or hour., The use of these arrangements I shall have to refer to when. speaking of' the time balls. This clock is in g:1lvanic connexion with the time-ball tower

,(lighthouse), the chronograph and the telegraph lines. . As it is necessary, by the above aq'angements, that the clock should be as nearly right as

possible at the moment of giving time signals, I have adopted a simple piece of mechanism, by which a subsidiary weight can be applied to the pendulum without any disturbance or necessity of opening the pendulum C:1se. The clock being kept with a losing rate, the weight is so' adjusted, that for every ten minutes it remains on the pendulum, it causes the clock to gain one second. This arrangement has been found to answer very satisfactorily.

The chronogra,phic apparatus has been in uninterrupted use since the last visit. It has never once been out of order, but. the chain which carries the driving weight has on one or two .occasions given momp.ntary trouble by slipping. I have every reason to be satisfied with this instrument., as it is extremely convenient in every respect, and rcquires but very little attention to keep it in ,order. I have altogether adopted Daniell's batteries for the supply of galvanic current, as being by far the most constant, and easily replenished; three cells are used on each of

,the recording circuits, and two small half-pint cells on the relays of each of the two clock circuits. Our galvanic train has been somewhat extended, facilities for altering the direction of the

U:.

currents,' and arrangements for giving time signals directly from the mean time clock, thr9ughout the"tEliegraph lines; has. been completed. A new" switching" apparatus, wit!:) a pair of relays, have been lately added to the train, by: means of which the currents of the chronograph and ,j

clocks can be turned in any direction that may be required, either within the Observatory or on : the teleo-raph lines of the colony. I shall be !\.ble to describe to the Board the properties of our '; chronoO'~aph anangements whilst they are inspecting them, and I think I maY,state without presu~ption that the galvaoic train of this Observatory is as complete as any in the world. ,

Time Balls and Signals.-The time ball on the lighthouse tower has been in unin­terrupted use during the year, and with one or two exceptions has always been correct in its indications. The signals-for the hall has always been dropped by hand-are given direct from the mean time clock, and are received on an ordip.ary Wheatston's needle. The position of the time ball, although perhaps the best that could be pbtained around the low shores of Hobson's, Bay, is not such as to render it so extensively seen as it would be in a more elevated place; therefore, the light signal which used to be given every night at eight o'clock, by means of eclipsing the lantern of the lighthouse before it was removed, was much preferred as a means of rating chronomoters in the Bay, inasmuch as not only was the suddenly eclipsing a brilliant light much more distinctly seen at a great distance than the drop of a ball could, but eight o'clock is a time when masters of vessels lying in harbor have more time to compare their chrollomoters themselves; and since the discontinuance of this signal, I have been urged by different maritime people, as also by the 'Chief HaI'bor Master, to resume the night signal if possible. After taking into consideration the best means of doing this, I have come to the conclusion of trying the Lime Light. This can be produced at a very trivial cost; the apparatus required will be simple, the burner even of a most brilliant light would be small, and an eclipsing shade therefore could be readily worked with the galvanic circuit. This would not only be visible to ships in the Bay, but to Melbourne and the suburbs, and for maoy miles around. It has further occurred to me that such a signal can be readily given from the tower of the new Observatory when it is completed, and in all probability be more extensively visible than from the lighthouse. I am about to make a few experiments to arrive at some conclusions as to cost, method of working, &c.

The same time signals by which the time ball is dropped are sent throughout the telegraph lines every day at one o'clock (Sundays excepted), by means of a repeating relay, and is managed thus-it is the duty of the manager of the telegraph at Williamstown to call all telegraph offices on the lines by a certain signal known as time-ball call, three minutes before one, at the same time to connect the Observatory wire with the main line. This sets an electric alarm ringing in the Observatory, whereupon the officer in charge of the time signals goes to the chronograph table, and by means of the switches places one of the clocks on the main line circuit, so that seconds' beats are sent throughout the lines as a preparatory signal, giving the operators an opportunity of adjusting the relays for any alteration of current that may have occurred; at one minute before one the circuit ,is. altered, and the mean time clock then gives the usual signals at the 20, 30, 40, 50, and five last seconds, the same as to the lighthouse. This arrangement has only been complete about a fortnight, and has hitherto worked admirably; previous to this the signals were seut by hand. .

A time ball has' lately been erected on the Telegraph Office, Geelong, aod is dropped by the above signals daily. There are also time balls at Cape Otway and at Ballaarat. The former has never been quite complete, the latter I believe is out of repair. I am of opinion that a time ball at Queenscliff would be very useful, much more than at Cape Otway, as ships often lie there for some days waiting for favorable winds.

Library.-There have been some importaot additions made to the library since the last visit of the Board, foremost among which are the Greenwich Observations, complete from the time of Bradley to 1858, comprising altogether seventy-five volumes, including two volumes of Lunar Reductions, and Hansen's "Tables de la Lune." These have been presented to the Observatory by the Lords Commissioners of the Admiralty, at the instance of Mr. Airy; one volume, Observations at,the Sydney ,Observatory for 1860, presented by the Rev. W. Scott, astronomer for N.S. Wales; one volume, by Colonel James, of' "Meteorological Instructions and Tables," presented by His Excellency Sir H. Barkly ; Meteorological Observations taken at Hobarttown, presented by F. Abbott, Esq. Struve's" Mensura Micometrica," Gouss's "Theoria motus corporum crelestium," Pearson's "Practieal Astronomy," and Sir G. C. Lewis's "History of Ancient Astronomy," have been purchased from the funds for the purpose. The item of' £50 for the purchase of books for the Observatory appears on the Estimates of this year, and should this pass, I hope to be able to make some further additions.

Observations.-Of these the greatest part consist of observations for determination of time, of position of instruments, and of the geographical position of the Observatory. A revision of all stars up to the sixth magnitude, within 10° of our zenith, has been commenced. The assistant astronomer has also undertaken a series of independent observations of circam­polar stars '; these, combined with zenith sector observations, occasional observations 6f occul­lations, and the regular series of meteorological and tidal observations, include all we have been able to undertake.

The observations for time determination are all made with the transit circle, and are considered of the first importance. NothiDg but bad weather is allowed to interfere with this portion of the observing, which also involves observations for position of instrument.

The determination of the geographical position of the Observatory has also been esteemed a matter of paramount importance, and the observations for this purpose are obtained on every available opportunity.

Observations ~f the Moon arid culmiriating stars are made on all occasions the weather will permit, and the results are sent to Greenwich every few months; all the corresponding observations that have been made there are received in return. We are then in a position to eomplete our longitude from Greenwicli, independent of any errors of lunar tables. The large error that accrues to the longitude, from the slightest error in observation, makes it very necessary to obtain an unusual number of comparisons before making any fresh assumption of longitude.

We have had 101 comparisons of Moon's R. A. with Greenwich, and 1 hoped to have had the honor of laying the result of these comparisons before the Board to-day, but 1 regret to say 1 am not quite prepared.

Since the arrival of the transit circle, observations in polar distance of most of the stars observed in R. A. have been made; this has almost doubled the labor in reducing.

The number of .observations made since the date of the last visitation is as follows :-

R. A. observations P. D. observations Z. sector observations Meridian observations of Moon,

3,774 2,129

194 126

These observations are all, with the exception of a portion of the polar distances, reduced, and are now being tabulated, as 1 propose to prepare for publication the results of them only.

Our observations, in the form ·of properly condensed results, with a clear exposition of the manner in which they have been obtained, will not cost much in printing, and will be quite 'as valuable to science, 1 believe, l1S volumes containing the whole detail.

1 trust the Board will induce the Government to publish these observations as soon as possible.

The determination of the errors of division of' the circle has not been completed. One or two sets of observations for the purpose have been made, but unfortunately proved unsatisfactory, on account of the instability of the l1uxiliary microscopes. These 1 have had more substantially 'fixed, and 1 intend repeating the observations, 1 trust, with better success.

The comet, No. iii., 1861, was observed throughout its visibility here. The transit ot: Mercury, which took place in November last, was also observed, though not successfully, owing to cloudy weather.

The determination of the boundary of South Australia and Victoria, with the length of the arc of parallel between the 14lst meridian and the Observatory, alluded to in my last report., is in progress, but not completed yet.

As the Board is aware, the new Observatory in the Government Domain, South Mel­bourne, has been commenced. Of the astronomical portion, the transit room only is complete; and as it would be impossible to carryon the work in that alone;1 have not deemed it advisable to disturb existing arrangements. 1 am nevertheless anxiously looking forward to the com· pletion of the new building, to move the instruments from their present unsuitable position.

The general work of the establishment has been seriously interrupted by the constant disturbance emanating from the railway,. which is in too great proximity to the Observatory. The traffic has been and is daily increasing, giving rise to an almost unremitting alteration in the adjustments of the instruments. The new fortifications, in which will be mounted some very l~eavy guns are now just completed, and 1 look forward with dread to the time when these are brought into use for drm and target practice. 1 have good reason to fear that the disturb­ance from this source will be almost fatal to the adjustments of our instruments.

The Board wiU see by the foregoing that the Observatory has beeri fully employed "ince their last visitation; indeed, more has been accomplished as regards the number of observatioll!l than it will be advisable to undertake again with our present staff. The great demand made on the Obscrvatory by the geodetic survey, for the past two years, has rendered very unusual efforts necessary; but the completion, in June last, of a very full working field-catalogue of stars, will somewhat lighten the hitherto over-arduous dutiea of the staff.

May 21st, 1862.

ROB. L. J. ELLERY, Astronomer.

By Authority: JOHN FERREll, Government Printer, Melbourne.