12 Domestic Science 



(i.e. that our measurement 3*74 inches is correct to ^ 

 or 0*005 inch) is a more probable statement. 



Too much emphasis cannot be laid upon the 

 importance of this point that in all experiments 

 involving measurement, every care should be taken 

 in the statement of results that full regard is paid to 

 the degree of accuracy of measurement of that quantity 

 which is least susceptible of accurate estimation. 



Where a measurement made is of less magnitude 

 than that of the unit involved, it is usual to write its 

 value in a decimal form, putting a zero in the units' 

 place, e.g. a line less than an inch in length may be 

 measured and its length said to be 0'86. . . inch. 



11. The above method of entry may appear at 

 first sight somewhat lengthy and troublesome, but 

 experience shows that only by making certain that 

 the work done can be described clearly and in full, 

 is it feasible to train one's powers so that what has 

 been done is retained and may be reproduced satis- 

 factorily. Space and time may of course be saved in 

 later work by making reference to that previously 

 done. Thus, should a scale similar to that described 

 above form part of the apparatus of a later experi- 

 ment, all that it will be necessary to enter concerning 

 it under the heading of apparatus will be : "A scale of 

 inches and centimetres as described in Experiment 1 ". 

 Similarly, the measurement of a straight line will not 

 be again described fully, but may simply be said to be 

 performed " as in Experiment 1 ". 



12. As a further exercise in the use of a scale, the 

 student should try 



EXPERIMENT 2. Draw a line CD 14*7 cm. long, 

 using the same scale as in Experiment 1. Measure 



