MO E. W. Morley — Self- Acting Mercurial Air pump. 



floor, by means of an air compressor in the basement. In 

 such a case the apparatus of Raps cannot be used. But with 

 my apparatus, the air compressor and air pump may be sepa- 

 rated to any reasonable distance. Further, one air compressor 

 may drive now one air pump and now another, or may drive 



several at once, with no change of adjustment other than turn- 

 ing a stopcock and an electrical switch. Also, my apparatus 

 requires no rubber tube in contact with the mercury of the 

 pump. 



Two air compressors and three pumps driven by them are 

 in constant and satisfactory use in my laboratory. It is not 

 claimed that the apparatus is superior to the admirable device 

 of Raps, but only that its peculiarities may in some cases be 

 advantageous. 



