154 



SCIENCE 



[N. S. Vol. LII. No. 1337 



The British Medical Journal reports that 

 professors of the Paris Faculty of Medicine 

 have heen placed in two classes according to 

 their seniority, those in the first class receiv- 

 ing a salary of 25,000 francs and those in 

 the second class a salary of 23,000 francs. 

 By a recent ministerial decree Professors 

 Eichet, Pouchet, Hutinel, De Lapersonne, 

 Gilbert, Roger, Nicolas, Eibemont-Dessaignes, 

 Quenu, Prenant, Widal, Chauffard, and Weiss 

 have been put in the first class, and Pro- 

 fessors Delbet, Marfan, Hartmann, Bar, 

 Marie, Broca, Teissier, Desgres, Lejars 

 Achard, Eobin, Legueu, Letulle, Couvelaire, 

 Carnot, Besangon, Vaquez, Dupre and Jean- 

 selme in the second class. 



DISCUSSION AND CORRESPONDENCE 



TRANSVERSE VIBRATIONS OF RODS 



To THE Editor of Science: In reference 

 to Professor Cady's paper on " The Theory 

 of Longitudinal Vibrations in Eods having 

 Internal Losses " in the Physical Review for 

 February, I should like to say that we 

 have made in the laboratory of Clark Uni- 

 versity during the last ten years a very great 

 many measurements of transverse vibrations 

 of rods of all sorts of materials and that we 

 find that the theory of viscosity is by no means 

 substantiated. Until Professor Cady's experi- 

 mental results are published I shall therefore 

 have to reserve my opinion as to the applica- 

 tion of this theory to longitudinal vibrations. 



I would say in justice to myself and my 

 students that our results have been held back 

 so long because we have attempted to apply 

 the theory of elastic hysteresis to the subject 

 and the difficulties in the solution of the 

 Volterra integro-differential equations in- 

 volved have been so great that we have not 

 been able to finish the theoretical results. 

 It looks at present as if that theory was not 

 substantiated either. Accordingly, it will be 

 necessary to invent a new theory or a com- 

 bination of both. I have now decided to pub- 

 lish the experimental results without waiting 

 for the theory and they may be expected to 

 appear soon in the Proceedings of the Na- 

 tional Academy of Sciences. The subject is 



an extremely interesting one and of great im- 

 portance for many reasons. 



Arthur Gordon Webster 

 Clark Unxversity, July 13, 1920 



THE EXPLORATION OF VENEZUELA 



To THE Editor of Science : With three com- 

 panions, I have just returned from a collect- 

 ing trip in western Venezuela, and I found 

 there some conditions which will probably be 

 of interest to others who may contemplate a 

 scientific trip in the tropics. 



At the present time in western A''enezuela 

 there is considerable activity in oil develop- 

 ment, not only in exploration, but in the 

 establishment of permanent camps and re- 

 fineries. Two of these camps are located in 

 country entirely different in character. Ar- 

 rangements could be made by any one desir- 

 ing to visit these camps to make them his 

 headquarters, thus rendering accessible for 

 study faunas and floras which the student 

 could otherwise reach and study only at con- 

 siderable trouble and expense. 



One of these camps is about twenty miles 

 from Maracaibo in a desert region. The 

 flora and birds here would be of especial 

 interest. 



The other camp is located on the Eio Oro, 

 a tributary of the Catatumbo, and is reached 

 by launch from Encontrados, a town about 

 ninety miles from the mouth of the Cata- 

 tumbo, which town can be reached by steamer 

 without change of boat from Maracaibo. 

 This camp is in a well watered and heavily 

 forested region, as I was told, but I did not 

 have an opportunity to visit the camp myself. 



The camp near Maracaibo belongs to the 

 Caribbean Petroleum Company, with offices 

 at Maracaibo. The other camp belongs to 

 the Columbian Petroleum Company, and 

 letters of inquiry relative thereto might be 

 addi-essed to Mr. David Brullenbourg, Encon- 

 trados. 



I was informed by several gentlemen con- 

 nected with both petroleum companies that 

 any one interested in the fauna and flora of 

 the region would be welcome at these camps, 

 and his expenses there would be reduced to 

 the minimum. These camps offord an oppor- 



