ERRATA. 



The reader is requested to make the following corrections and then destroy this slip. 



Page 45, line 20, for " derived " read " desired ". 



Page 65, line 4 from bottom, for " altitude " read " attitude ". 



Page 117, line 13, for " kmax$ " read " famaxS". 



Page 207, for " Tests on model wings, 78 " read " Tests on model wings, 87 ". 



Page 207, for " Wire, stream-line, 9, 150 " read "Wire, stream-line, 9, 82, 150". 



