The study of the problems connected with a successful racing sailing boat, like Gaul, can be divided into three parts. There is first of all the general configuration of the hull upon which lately much study has been directed. Anybody interested in this should look up the article, “Model Tests of Sailing Yachts,” by Kenneth S. M. Davidson, Director, Experimental Towing Tank, Stevens Institute of Technology, New Jersey, appearing in the August issue of “The Rudder,” in which it will be noted model hulls are pulled through the tank at an angle of heel, and with an angle of drift.

In certain types of aeroplane the empennage is carried on two tail booms emanating from the main body. In some cases the booms and tail plane form what is virtually a portal and in these circumstances a fairly simple approximation may be found for the stresses resulting from fin and rudder side loads. The method adopted follows the treatment given in the author’s paper, “The Stressing of Rigid Jointed Frames.”