Assembly Line

• Astrology and Astronomy• Mechanical clocks• Sextant• Huntsman steel• Precision in manufacturing• The lathe• Standard interchangeable parts

600-539 B.C.

• Astronomers divided the sky into twelve constellations (clusters of stars), 30 degrees apart in 360 degrees.

• This marked the beginning of the pseudo-science astrology.

760AD- Caliph, Al Mansur became ill

• Seemingly cured through assessment of star positions and Gundeshapur medicine.

• Lead to increased study of star positions and improvement of the Astrolabe.

Translated Arab into Latin

• The Almagest (Arab translation of Ptolemy’s star table) and many other texts were translated into Latin during the 12th century.

1276 – Alfonsine Table Is Standard Star Reference

• By 1276 the king of Castile ordered a compilation of star tables called the Alfonsine Tables. Later these star positions were worked out for Paris and other places.

When Is It Time to Pray

• St. Benedict specified certain activities at certain times of day and night which led to the water alarm clock.

• 11th Century – Water alarm clock (Clepsydra) developed.

A Modified Clepsydra

First All Mechanical Clock

Verge and foliot escapement

1290AD -Verge and Foliot Escapement

• This all mechanical clock was widely used by priests.

• By 1400 AD clocks were telling people when to work. It increased productivity.

• Accurate to within 15 minutes per day.

Verge and Foliot clock in action

A Venetian 24hr Clock

AM and PM

• AM comes from Latin for “ante meridian”,which means before noon.

• PM comes from Latin for “post meridian,” which mean after noon.

• The 12 clock chimes are easier to understand.

1450 AD portable clocks

• Driven by a carbon steel spring and controlled by the Fusee

• Carbon steel was made by heating carbon and iron together, then hammering off the hard carbonized steel.

FuseeSpring driven barrel

Blister Steel

1608- Lippershey’s“Looker”

• A telescope intended for military purposes but led to Galileo to confirm Copernicus that the Earth is not the center of the universe.

John Dollond’s Achromatic Lens 1758

• Early telescope lenses bent different colors differently resulting in a blurry image.

• Dollond’s lense was made of Flint and Crown glass both canceling each others color aberrations. Result was a sharp image.

The Pendulum Clock

• Galileo’s experimentation of pendulums led to Huygen’s, pendulum clock.

• First ones only accurate to 10min/day.• By 1725 engineered escapements

allowed accuracy within 1 second per day. Nevertheless, this clock was useless at sea.

Modern Escapements

• A British clockmaker George Daniels invented the co-axial escapement first used by Omega SA in 1999.

• The design uses radial friction instead of sliding friction. Resulting in longer life and improved accuracy.

• See the Daniels co-axial escapement in action

Verge and Pendulum Escapement

How it works

1731 – John Hadley’s sextant

• A precise astrolab, capable of measuring angle between two objects such as the sun and horizon.

• The first measuring arcs were etched by hand so they had limited precision.

1740 – Huntsman Steel

• Benjamin Huntsman was a clock maker dissatisfied with current steel quality. He developed ”crucible steel.”

• Extremely hard uniform steel perfect for clocks.

• Helped to trigger the industrial revolution.

See how steel is made today

1774 – Jesse Ramsden’s Dividing Engine

• Triggered by Hadley’s sextant, which demanded more precise arc divisions.

• Jesse Ramsden’s Dividing Engine used a steel tangent screw made using a Huntsman steel cutting tool.

The Dividing Engine

Interchangeable Parts

• Honore Le Blanc in France gave the idea of interchangeable parts for making guns to Thomas Jefferson.

• USA in 1798 became first to make guns with interchangeable parts.

1808 – Maudslay’s Lathe

• Used in England to make ships blocks in the worlds first modern assembly line. His lathes were extremely precise

First Standardized Assembly Line

• Terracotta Army

• Assembled 2200 years ago.

• >1800 life size soldiers, weapons, horses, chariots.

Ship Blocks• These are simple

pulley systems.

• Force is reduced by 1/n where n is number of lines or pulleys supporting the load.

• Four pulleys make 100 Lbs feel like 25 Lbs.

Work = force x distance

Automation not a threat here

• Much cheap unskilled labor in USA.

• Interchangeable parts and the assembly line led to great growth in jobs and exports.

• Later, time/motion studies by Taylor and Gilbreths perfected the assembly line.– Ford’s B-24 Bomber

Accuracy

• Closeness to true value

• The accuracy of an analytical measurement is how close a result comes to the true value. Determining the accuracy of a measurement usually requires calibration of the analytical method with a known standard.

Precision

• Reproducibility of results

• Precision is the reproducibility of multiple measurements and is usually described by the standard deviation, standard error, or confidence interval.

Accuracy and Precision

Taking the long way home

• John Harrison’s highly precise clock designed for ships.

• Solved the longitude problem.

• 15 degree longitude (approx. 1000 mi) per hour.

Harrison’s H4

• Completed in 1759• 13 cm (5.1 in) in

diameter and weighs 1.45 Kg (3.2 Lbs).

• Off by only 39.2 s/47 days or 0.83 s per day

• Better than twice the required precision.

Harrison’s H5

• Tested by King George III in 1772

• It was off only 0.3 second/day

• Harrison did not received the £20,000 “prize” from the Board of Longitude in his lifetime.

Time & Longitude

• 15o/hr or approx. 1000 mi/hr

• Check “home” chronometer from ship at “high noon”

Home time

Δ time

Home is

You are

1PM 1hr 15o E 15o W

2PM 2hr 30o E 30o W

10AM -2hr 30o W 30o E

Longitude

• An international conference in 1884 set the Royal Observatory in Greenwich England as zero longitude.

• A laser beam shoots North along the prime meridian.

Readings: “Taking the Long Way Home”

• Longitude lines are the vertical meridian lines. Zero longitude is Greenwich England.

• Latitude lines are the horizontal lines. Zero latitude is the equator.

• The longitude of South tip of Africa is approx. 20 E longitude & 35 S latitude.

• S. tip of S. America is approx. 75 W longitude & 55 S latitude

What you should know

• Differentiate between astronomy and astrology.

• Why 12 months in the year and 12 hours each day and night.

• Differentiate between accuracy and precision.

• Operation of water alarm clock, mechanical clock, portable clock and pendulum clock.

• Astronomy is a science

• From 12 moons/year

• Slides #27-29

• Slides #7-12 and #15-17

What you should know

• Why did astronomers prefer the pendulum clock.

• The Latin and English translation for AM and PM.

• The connection between the “looker,” the sextant, and the need for more precision fabrication.

• Why was le Blanc unsuccessful installing his standardized gun parts in France? Pg. 150

• Increased precision

• Ante and post meridian

• Slides #18-21

• It threatened gunsmiths in Europe.

What you should know

• How a lathe works

• The connection between Huntsman steel (crucible steel), the lathe, tangent screw, dividing engine and the sextant.

• How ships blocks work (LN).

• Why the assembly line flourished in the U.S., not in Europe.

• Burke 144, video

• Slides #19

• Divides work by number of pulleys #25

• Cheap, abundant unskilled labor in the U.S. not in Europe.

What you should know

• How the American System of Manufacturing affected U.S. citizens and military

• Sailing from London at high noon your chronometer reads 2:00PM? What is your new longitude?

• Describe the construction of Dollond’s achromatic lens

• Corrective lenses 1300, the “Looker” 1608, why did it take 300 years for this?

• Burke 149-151.

• London is ahead (East) so you are West 2hr x 15o/hr =

30o longitude. #33-35

• Burke 141 & slide 14

• Burke 134-5