July 10, 1903.] 



SCIENCE. 



57 



of Callendar with tlie same apparatus, de- 

 scribed in the British Association ' Report ' of 

 the Toronto meeting, 1897. I have thought it 

 worth while to test the same for solids. Car- 

 bon was the substance chosen, as being a con- 

 ductor and as having the greatest known 

 variability of specific heat with temperature 

 and, therefore (presumably), with other dis- 

 turbing factors. The metho(J employed was 

 to heat a fine carbon rod by a heavy current, 

 and watch its expansion by means of an optical 

 lever. 



If a vessel containing a given quantity of 

 water have its capacity suddenly altered by a 

 bulging or a constriction of its sides, the re- 

 sult will be a change of level of the water. 

 And if the specific heat of the carbon rod be 

 suddenly altered when the current is started or 

 stopped there should be observed a change of 

 temperature which I hoped to detect by an 

 abrupt alteration in the length of the rod. 

 The results were entirely negative. The rod 

 used was of French make, a Carre electric 

 light carbon, 51 cm. long and 0.15 cm. diam- 

 eter, wrapped in tissue paper and enclosed in 

 a glass tube. Its resistance (cold), according 

 to the nature of the contact made, was from 

 about eleven ohms upwards. The rod was 

 mounted vertically, its lower end resting in 

 a mercury cup, and its upper end tilting a 

 small lever on a knife-edge bearing. On this 

 lever was mounted a galvanometer mirror. 

 The current was taken from the upper end of 

 the rod by a wire wrapped tightly around it. 

 The tilting of the mirror was read by means 

 of a telescope and a vertical scale placed two 

 and one half meters away. The current used 

 was three amperes. When the current was 

 started or stopped a perfectly steady motion of 

 the scale was observed. A jolt of 0.05 cm. 

 in the field of the telescope could have been 

 detected. 



As about 6 cm. of the scale passed the cross 

 wires before the still damp mucilage holding 

 the tissue paper around the carbon began to 

 steam, it will be seen that a jolt of 0.05 cm. 

 would have meant a change in temperature 

 of about two thirds of a degree, taking the 

 initial temperature of the carbon as 20°, or 

 293° absolute. And a difference of level of 



two thirds of a degree in 293° would have 

 meant an alteration in the heat capacity of 

 about one part in 450. Paul R. Heyl. 



The Randal Morgan Physical Ladoratoby, 

 University of Pennsylvania. 



the proposed biological l.ujou.^tory .\t the 



TOKTUGAS. 



To THE Editor of Science: In Science, 

 June 12, 1903, is a letter by Professor C. B. 

 Davenport upon the proposed biological sta- 

 tion at the Tortugas. There are two sen- 

 tences in it which I feel it necessary to com- 

 ment upon. The first is : ' On the Pacific 

 coast we have the Hopkins laboratory and 

 that of the University of California.' The 

 second is : ' While we are i^lanning a chain 

 of marine stations certainly * * * Puget 

 Sound should be considered.' No doubt Dr. 

 Davenport, who is quite familiar with the 

 fact that the Minnesota Seaside Station at 

 Port Renfrew, British Columbia, is just en- 

 tering upon the third year of not altogether 

 unsuccessful effort, means by ' we ' the biol- 

 ogists of the United States. Under this con- 

 struction it is altogether proper for him to 

 omit the Minnesota Seaside Station from his 

 calculations. In view of the fact, however, 

 that this station, although upon Canadian 

 soil, from which a number of memoirs and 

 one volume of the yearbook, Postelsia, have 

 already been published, is managed in connec- 

 tion with one of the American universities 

 and has drawn its clientele principally from 

 the western United States, it seems proper 

 that it should be included as one of the Pacific 

 coast stations of America. Its position on the 

 Straits of Fuca was selected with great care 

 so that it might be accessible as a center for 

 the study of the fauna and flora not only of 

 the sound but also of the open sea. 



The Minnesota Seaside Station has not 

 passed through the stage of an extended dis- 

 cussion in the columns of Science, nor has it 

 intimated its pressing wants to Mr. Carnegie 

 or any other millionaire. It has risen quite 

 peacefully and modestly upon a cooperative 

 basis which is none the less favorable for re- 

 spectable work. Every year has seen consid- 

 erable improvement both in its buildings and 



