OF ARTS AND SCIENCES. 325 



16. In the above paragraphs I have endeavored to exhibit the 

 stage of progress attained iu the work on molecular pressure, at the 

 time when it had to be abandoned ; for the calorimetric work can 

 only be satisfactorily done in midwinter, Cf. §§ 5, 6, 7. It will be 

 seen, I think, that the subject, as a whole, is ripe for sharper tests, 

 and the work will therefore be resumed at an early opportunity. 



Physical Laboratory, U. S. G. S., 

 Washington, D. C. 



