A YEAR IN SCIENCE 19 



the instructor. How much of an error did you make? 

 How do you account for this error? 



E. Comparison of the English and metric units of 

 volume. 



Use a liter vessel, a quart measure, and a set of 

 metric weights. 



(a) Find by measurement, using water, which is 

 larger, a liter or a quart. 



(b) Weigh a liter of distilled water. First balance 

 the dry liter vessel, then fill with distilled water and 

 weigh. Find the temperature of the water with a 

 centigrade thermometer. 



(c) Weigh a quart of distilled water. Use the same 

 method as you employed in weighing the liter of water. 



(d) Find the relation of a quart ^o-a liter from your 

 data of (c). Ask the instructor to verify your results. 

 How accurate has your work been? Does the tem- 

 perature of the water have anything to do with its 

 weight? Can you think of reasons for any errors 

 that you may have made ? 



Exercise 3. Does Gas Have Weight? 



Object: To determine whether gases have weight. 



Apparatus 



Balance and weights Incandescent lamp bulb 

 Hollow brass globe with (burnt out bulb) 



stop cock Bunsen burner 



Air pump Blow pipe 



Directions : A. On one pan of the balance place the 

 brass globe. Upon the other pan place enough weights 



