Early Mechanical Computers 2

Samuel Morland

1625 - 1695

Attend university at a later age (due to political strife in England)

Recieved BA for mathematics (instead of clergy)

A capable mechanic: Calculating machines to barometers, speaking trumpets, and water pumps

How Morland’s adding/subtracting machines worked

Implemented a partial manual carry

Was pocket sized

Could do subtraction in the opposite direction

Other Morland designs

Other machines for multiplication, division, squares and cubes using Napier bones in a circle

Morlands Machine

No physical version of this machine was ever constructed or non have survived

Rene Grillet

Little to nothing known about this man (no birth or death date)

One source says he was a prestigious clock maker to a royal

Second source says he exhibited machine in county fairs for a silver (paid people to look at his machine)

Date Grillet published his work on his calculating machines

In 1698 he published information about his machine

The ‘marketing brochure’ only made claims on what it can do (everything) and how to buy it (no explanation on how)

Morland’s vs Grillet’s Machines

According to Manuscript of Chales Babbage, Morland’s machine had more useful mechanisms using Napier’s bones, while Grillets had a large capacity adding mechanism

Grillet’s Machine

No machine survived to today

Automatic or manual carry is unknown

Unknown of its significants and how it worked

The 3 commercially produced mechanical calculators

1. The Thomas Arithmometer
2. Baldwin-Odhner Machine
3. Key Driven Machines: Comptometers

The Thomas Arithmometer

From 1820s \~ 1914

M. Charles Xavier Thomas de Colmar applied modern engineering to Leibniz mechanism

Created an industry where mechanical devices were used to aid calculations

Device is large (whole desk, two strong people to carry)

Could handle 7-8 digits, produce 14-16 (because it can handle multiplication)

Special extensions could handle 16 digits and output 32 digits

Impact of the Thomas Arithmometer

Created an industry where mechanical devices were used to aid calculations

Baldwin-Odhner Machines

1885 - \~1965

Two machines created in different places (Baldwin/NA, Odhner/EU)

Used a variable tooth gear such that number is the number of protruding teeth

4 function calculator that could sit on the corner of a desk

Awkward UI and time consuming

Saved space and easy to use

Ex. Data entry using sliding mechanisms

Tooth gear mechanism

Number of teeth would stick out representing the digit

Multiple layers representing each digit of number

Frank S. Bladwin

Baldwin machines in America (US)

W. T. Odhner

Odhner machine in Europe (Russia)

Mr. Dorr E. Felt

Created functional key driven machines called comptometers

Developed prototype N. Y. D: 1885

First working model made in Autumn of 1886

Used a macaroni box, meat skewers and elastics to create

Advantages to key driven machines

Speed up addition operation significantly compared to other mechanical calculators

History of first key driven machine

Developed by Mr Dorr Felt

What mechanism was the Thomas Arithmometer based on?

Leibniz

Who came up with a functional key driven machine called Comptometers?

Felt