310 Mr. Atwood’s Disquisition , &c. 
because cos. i F x cos. S — sin. { F x sin. S = cos. \ F 
x cos. S x 1 — tang. |F x tang. S 
WO — FE X t an g‘^ Fx sin -l F X tang. S x i— tang. ^Fx tang. S 
^ cos.-fF x cos. S x i — tang.fF x tang.S x v' i — - tang. 1 ! F x tang. a S 
or W? - FF : tans -^ F x tang - s x sec ~ s 
^ V i — tang. a -| F x tang. 1 6 
The work of Mr. Chapman, meritioned in page z6j, is written in the Swedish 
language, and has been translated into French by M. Vial de Clairbois. The 
translation is intitled, Traite de la Construction des Vaisseaux, & c. par Frederic 
Henri de Chapman, Premier Constructeur des Armees Navales, See. 
