PAPERS ON CHEMISTRY AND PHYSICS 243 



of gas by means of an ordinaiy Jolly calorimeter with 

 the usual resulting values falling far below the values 

 required of gas companies by law, or to accept the legal 

 calorific values and by using an ordinary gas stove de- 

 termine the cost of operating that stove for one hour! 

 Or, possibly, compare the cost and efficiency of the gas 

 stove with an electric stove of similar size ? 



As I have passed through our laboratories during the 

 past 10 or 15 years, I have been impressed with the 

 thought that there is some tendency to substitute, to a 

 certain extent, practical utilitarian appliances such as 

 are seen daily in use in the ordinary walks of life for ap- 

 paratus never met with outside the laboratory and used 

 solely to illustrate or demonstrate the laws and principles 

 of science. 



I have recently been interested in looking through a 

 new laboratory manual of physics. Of the first 25 ex- 

 ercises, 13 are instructions for setting up models of ap- 

 pliances in common use and involving physical principles. 

 The author explains that each student is to be provided 

 with a locker equipped with a supply of glass tubing, 

 lamp chimneys, rubber tubing and rubber stoppers, pinch- 

 cocks, Florence flasks and stich other raw materials as 

 will enable him to construct models of useful appliances. 

 "Without counting them, I should say that about one-half 

 of the exercises outlined are intended to be of this char- 

 acter. Probably the other half can safely be described as 

 being of the old ty|)e, i. e. exercises planned to illustrate 

 the truth of stated laws and principles and, in the main, 

 using apparatus never used outside the laboratory. 



^liile this laboratory manual interests me, and while 

 I regard it as something of an innovation in laboratory 

 practice, still I cannot approve of the method as a whole. 

 Exercise 1 is ''To construct a lift pump and explain its 

 action". Materials required: ''No. 50 Macbeth chimney; 

 12-oz. bottle: 12-inch, solid brass piston rod, diameter 

 6 mm. with cotter pins : 12-inch glass tube, outside diame- 

 ter 7 mm. ; No. 7 one-hole rubber stopper : No. 6 two-hole 

 rubber stopper (one hole at the center) ; thin leather 

 sheeting and tacks." Illustrations and description of the 



