304 



Some Properties of a Rampant Arch, 



Then by Trig. rad. t log. 2r: :cot. B : log. a. (See Fig. 1.) 



And put V2r^+a^=b. 

 Again by Trig. rad. : log. r: ."cot. A : log. c. (See Fig. 2.) 



And iput' \/r^+c^=d. 

 Then by sim. tri. d : C'.a : e; and put ^1^ — 6"=/. 

 Again by Trig. rad. ; log. c; : tang. B : log. g. 

 Then put ^/g^-\-c^ =h, and Vr' -}-g^ =i ; also let i-r~j. 



