S64. 



Dr. B. D. Steele on an 

 Fig, 1. 



To wr£ff Pi/Mp 



The reservoir B is connected with the water-pump by the 

 tube e, and to present the possibility of water entering B, 

 this tube is made 85 cm. long and is provided at its lower end 

 with a mercury trap, s, o£ special design. 



