6go Mr. button’s Calculations to afcertain 
of inventing and defcribing fuch modes of computa- 
tion as fhould be proper to be applied in fo important 
And delicate a bulinefs. Having, at length, with clofe 
and unwearied application for a coniiderable time corn- 
pleated all the calculations ; I have, in the following 
lheets, drawn up an account of thofe operations, with 
the refults arifing from them; and have accompa- 
nied them with fuch drawings as are neceffary to il- 
luftrate the deferiptions. I have alfo inferted a fynopfis 
of the meafures which were taken of the lines and an- 
gles, from which any perfon may at any time fatisfy 
himfelf of the truth of the computations that have been 
made and are herein defcribed. Thefe meafures I have 
here immediately fubjoined, before I proceed to defcribe 
the computations made from them- 
A fynopfis 
