200 RECORDS. 



the hull, spars and sails, an expression is found for the "theo- 

 retical speed," or speed the yacht should make under normal 

 conditions. While every little detail of hull and rigging con- 

 tributes its part in producing a fast yacht, yet it is manifestly 

 impossible to take account of all such details in finding the 

 "theoretical speed" ; only the main factors can be considered. 

 These factors, which enter the rules in common use, are length 

 of hull, sail area and displacement. 



It was shown that the rules introduce these factors in such 

 a way as to involve the assumption that speed is proportional 

 to : {a) The square root of length ; (d) the fourth root of sail 

 area ; and that the New York Yacht Club rule involves these 

 two assumptions and the additional one that speed is propor- 

 tional to (c) the inverse sixth root of displacement. 



Dr. Poor discussed these assumptions in detail and showed 

 that, while there is some apparent basis for the assumption in 

 regard to length, their appears to be no scientific basis for those 

 in regard to sail area and displacement. In fact, the available 

 data seem to point to the conclusion that the assumption in 

 regard to sail area is wrong, that speed is more nearly propor- 

 tional to square root of sail area. In support of this view the 

 results of many races between two yachts in 1902 and 1903 

 were used. Dr. Poor called attention to the scientific aspect of 

 the problem, and suggested several lines of experiment, by 

 means of which the relationship between speed and the factors 



of measurement could be determined. 



S. A. Mitchell, 



Secretary. 



SECTION OF BIOLOGY. 

 November 9, 1903. 

 The November Meeting of the section was held on the 9th 

 of the month at the American Museum of Natural History, 

 Professor Brashford Dean presiding. A business meeting of 

 the Section preceded the scientific program. Professor E. B. 

 Wilson was nominated to the Council as vice-president and 

 chairman of the Section of Biology for the coming year. M. 

 A. Bigelow was re-elected secretary of the section. 



