Select mechanical exercises: shewing how to construct different clocks, orreries, and sun-dials. On plain and easy principles. With several miscellaneous articles, and new tables. I, for expeditiously computing the time of any new or full moon within ... 6,000 years before and after the 18th century ... II. For graduating and examining the usual lines ... To which is prefixed, a short account of the life of the author / by James Ferguson.

  • Ferguson, James, 1710-1776.
Date:
1778
Catalogue details

Licence: Public Domain Mark

Credit: Select mechanical exercises: shewing how to construct different clocks, orreries, and sun-dials. On plain and easy principles. With several miscellaneous articles, and new tables. I, for expeditiously computing the time of any new or full moon within ... 6,000 years before and after the 18th century ... II. For graduating and examining the usual lines ... To which is prefixed, a short account of the life of the author / by James Ferguson. Source: Wellcome Collection.

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    aa er SY Fe aan IS as ae Se On eg = Ste Se RN ae SF Ey PO BE mnt Foes SELECT EXERCISES. 4a4t The Sector is prmcipally ufeful as a univerfal plain Scale, fitted to any radius within the compafs of its open- ing; only obferving that the equal Parts, Sines, Chords, and Tangents under 45 degrees, are not taken along one line, as on the plain Scale, but acrofs the Sector from any degree on one leg to the fame degree of the fame line on the other. | The Gunter’s lines are for readily working proportions; in which, re- gard mutt be had to the terms, whe- that the firft and third term may be of the fame name, and the fecond and fourth of the fame name likewife: then, raifing your proportion accord- their proper line, from the firft term to the third, in your compaffes; and applying one point of the compaffles to the fecond, the other applied to the right or left according as the