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In the mid 19th century Aaron Lufkin Dennison became inspired by the manufacturing techniques of the United States Armory at Springfield, Mass. The "armory practice" was mainly based on a strict system of organization, the extensive use of the machine shop and a control system based on gauges. Aaron Dennison proposed to produce watches via these techniques and, along with a few others, founded the Waltham Watch Company.

In the rest of the world manufacturing involved making certain parts under the roof of a factory and obtaining other parts from piece workers who used their own cottages as workshops.

The American System of manufacturing by interchangeable parts meant the establishment of working facilities for the entire manufacture. It meant that everything was made on the premises, not according to the plans or ideas or methods of work of individual workmen, but under the direct supervision of a company's foreman, according to gauges the company furnished, under conditions of time, cleanliness and care which the company prescribed.

Waltham soon found that it was necessary to invent, develop and build its own production machinery, special gauges systems adjusted to the smallest watch parts dimensions, new alloys & materials.

The chronology of production lessons at the Waltham Watch Company can be divided into three phases:

• 1849-1857 learning and experimenting
• 1858-1870 refining and gauging
• 1871-1910 automating and factory organization

The manufacturing of watches differed from other products that had earlier used the armory practices in two significant ways.

First, the high price of watches allowed for a large investment in research and development. The vast majority of the price of a watch was due to labor rather than materials and any system that could significantly reduce labor costs could significantly increase profits. Even after 40 years of manufacturing improvements, in 1910, labor accounted for 80% of the cost of watches made by the Elgin National Watch Company.

Secondly, watches require very strict tolerances and very few manufacturing defects. Previous products made via armory practices, such as fire arms, sewing machines, etc. had tolerances 10 to 100 times as loose. A watch gear that is offset by a few thousands of an inch from where it should be will cause increased friction, losing critical power that needed to be sent to the balance wheel and greatly accelerating the wear of the watch. Previous watch manufacturing techniques required expert watchmakers to recognize slight variations in part sizes in order to place each gear in the correct location or to make other adjustments during the manufacturing of each watch.

In order to reach these strict tolerances, watch manufactures largely manufactured their own machine tools and machine parts. Elgin manufactured almost two drill bits for each watch they manufactured. The knowledge of how to manufacture machines that could manufacture watches spread from Waltham to Elgin to dozens of other American watch companies and manufactures of other products. Techniques such as jigs, stops and measuring devices on machines were not just refined, but other techniques were developed also. For example, statistical methods were used to reduce wastage. If a gear staff (axel) and a jewel bearing hole were designed to be a given size, then the parts that most closely met those design goals were used in the highest grade watches, while staffs that were too large would be matched to watch jewels with holes that were too large and together they could be used on lower grade watches.

[edit] References

• Hoke, Donald Robert; The Time Museum Historical Catalogue of American Pocket Watches; Time Museum Rockford, Illinois, U.S.A.

[edit] See also

• E. Howard & Co.
• Waltham Watch Company
• Elgin Watch Company
• Armory practice

[edit] External links

• Boston The Cradle of American Watchmaking
• The Boston Watch Co
• Origins of Waltham Model 57
• Time Museum Rockford, Illinois, U.S.A.
• Philadelphia Exhibition 1876 Report to the Federal High Council by Ed. Favre-Perret (1877)
• American and Swiss Watchmaking in 1876 by Jacques David
• The Watch Factories of America Past and Present by Henry G. Abbott (1888)
• Watchmaking and the American System of Manufacturing (2009)