J-28 



SCIENCE. 



[N. 8. Vol.. XVI II. Xo. 4(16. 



' 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 assump- 

 tions that speed is proportional to : (a) The 

 square root of length; (b) 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 proportional to 

 (c) the inverse sixth root of displacement. 



Dr. Poor discussed these assumptions in de- 

 tail and showed that, while there is some ap- 

 parent basis for the assumption in regard to 

 lengrt;h, there appears to be no scientific basis 

 for those in regard to sail area and displace- 

 ment. 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 proportional 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 sug- 

 gested several lines of experiment, by means 

 of which the relationship between speed and 

 the factors of measurement could be deter- 

 mined. S. A. Mitchell, 



8ecreta7-y. 



CLEMSON COLLEGE SCIENCE CLUB. 



At the meeting of October 17 Dr. R. N. 

 Brackett discussed ' An Improved Welsbach 

 Mantle.' A brief historic review of Wels- 

 bach's work in originating and perfecting the 

 mantle which bears his name was given. The 

 experiments in varying the proportions of the 

 rare earths and observing the effects produced 

 were mentioned. As a result of these experi- 

 ments, the best results seem to be obtained 

 with a mixture of the rare earths in the pro- 

 portion of approximately 99 parts of thoria 

 to 1 part of ceria. The explanations which 

 have been offered for the phenomena observed 

 in the use of the mantle were mentioned. 

 The recent improvements by which the mantles 

 have been hardened and thus adapted to use 

 in railway trains, etc., were pointed out. 



Professor Chas. E. Chambliss read a paper 

 entitled ' A Destructive Rice Pest.' The 

 speaker referred almost exclusively to his own 

 observations made in the rice fields during the 

 early spring and late summer. The pest t(. 

 which reference was made was the bird known 

 locally as the rice bird, and in the north as the 

 bobolink. The habits of the bird in the rice 

 fields of the south, where it stops only on its 

 way to and from South America and the 

 northern United States, where it breeds, were 

 mentioned. Also the extent of the damage 

 done by the birds on their first and second 

 visits to the fields was pointed out. The two 

 methods in use at present for combating this 

 pest were given. These consist in tarring tin: 

 grain, previous to sowing, and in frightening 

 the birds by the explosions of firearms. The 

 first method is used only in a limited way, 

 the second being the one almost universally 

 employed. The speaker referred to the in- 

 efliciency of both methods, and according to 

 his observations the bird is more easily fright- 

 ened by the passing of shadows than it is by 

 firearms. The possibility of the use of trained 

 hawks for combating this pest was pointed 

 out. 



The next and last paper on the program 

 was ' Cultural Studies of a Nematode,' by 

 Dr. H. Metcalf. Under this title there was 

 given an account of investigations into the 

 cause of decay and ' damping off ' in a number 

 of different plants. A nematode, a Fusarium 

 and several bacteria were found associated 

 with the disease. It was necessary to devise 

 special methods for isolating the nematode. 

 Final results of inoculation indicated that the 

 plant organisms were the direct cause of the 

 decay, but that the nematode played an im- 

 portant part in spreading the infection. By 

 way of illustration living specimens of the 

 nematode were projected on the screen. This 

 paper will be published in the Proceeding-^ 

 of the American Microscopical Society. 



F. S. Shiver, 

 Secty.-Treas. 



Clemson College, S. C, 

 October, 1003. 



