Transactions Socwtv Naval Architects and Marine Engineers, Vol. 2^, 1915. 



Plat. 



e 4. 



To illustrate paper on "Aerodynamical Experiments upon a Yacht's Mainsail, 

 by Professor H. A. Everett, Member. 



"To P ^fj^" " < I 



C - Weight" in Scale Pan o-f T'rarksvet's,^ Avtti. 



O - VVeigMT ih ScaJe Pot o^ Lon^ttudihal Arm. 



t^ - MomehT of Soil aboMT MqsT. 



"* *** c - f v-Qhsvet-se Componenf of Force on Soil. 



Win J, 



' d - LjOftgitodih«il Com poheht of Force oh 3q''- 



©-Angle of Boom to Wind. 



X-Cooi-eJinote of Center of Press ufe a'ohg 



Line of Wi'hd. 

 ij -CoordinoTe of Cehter of Pressure across 



Lihe of Wind, 

 z - Height of Center of Pk'essure oboveTbpof 



Boom at Most- 

 JL -HcKjht ofBot. of Boorn at fV\ast aboye piuot, 



SL, m 30.<t 5 inches, Jtz= Sf.OS inches. 



c, d, x^(j,z, arc unkriown (fuohtities to 

 he computed. 



The forces ocTin^ on the soil are referred to the 

 piahe of the boom and mast. 



SIGNS 



,-«■«' 



E'«^uot)ons for Soltitioh of c,d,)t,«j,z. 



?5C, = cU, + 2). 

 36C^ = c(j^+2) 

 36D, "d(i,+ z). 

 36Da=cl(JBg + 2). 



AA = CX+ dy. 



