Viewing page 16 of 19

This transcription has been completed. Contact us with corrections.

^[[15]]

One of the first Dividing Engines, designed and constructed by Jesse Ramsden of Piccadilly, London, England, in 1774-5, together with the Slide Rest, with which the screws and gear cutters of the machine was made, was deposited by Dr. Henry Morton, President of Stevens Institute of Technology, Hoboken, N.J.

A Sextant, which was graduated by this dividing engine in 1775, was so accurate that the English Board of Longitude, "ever ready to remunerate any successful endeavor and to promote the lunar method of determining longitude at sea", conferred a reward of ^[[£]] 615 to Ramsden, on condition that the engine should be at the service of the English instrument makers, and that he should publish an explanation of his method of making and using it. 

A quarto pamphlet containing this information was published in 1777, with a preface prepared by Nevil Maskeline, Astronomer Royal, dated Greenwich, Nov. 28, 1776. 

It is interesting to note in this connection that the circles of the great theodolite, with a 36 inch telescope, (still preserved at Greenwich), which