226 



The Ottawa Naturalist. 



[February 



ish, so that when the individual parts are finished they will fit 

 accurately together and form one harmonious whole. When these 

 drawings are completed, patterns must be made for the parts to be 

 cast in iron or brass. 



In making the patterns the amateur must have some know- 

 ledge of the moulder's trade in order to make the proper allowance 

 for drawing the patterns out of the sand, for the contraction of the 

 metals in cooling and for coring the hollow parts The shapes of 

 hollow parts cannot be made in ordinary sand, which would not 

 stand up ; but core boxes must be constructed in which are made 

 the hard baked sand cores which are knocked out of the holes after 

 the casting is done. The steel forgings are made directly from 

 the drawings and do not as a rule call for patterns. To do this 

 the amateur must be somewhat of a blacksmith. 



After the castings and forgings, comes the machining of the 

 parts, which falls to the lathe, sharper, or drill, as required. In 

 addition to this there is a certain amount of bench work such as 

 scraping, filing, tapping for screws and general fitting. It will be 

 seen that in these manipulations the amateur has been in part a 

 draughtsman, pattern-maker, moulder, blacksmith and machinist, 

 and if he complete the engine and run it he will learn some of the 

 duties of a fireman and an engineer. He will have acquired an 

 'ncreased respect for each of these arts and for the men who prac. 

 tice them well. 



One of the chief benefits of the mechanical hobby to the indiv- 

 idual is the training of the faculty of accuracy. 



To work to definite measurements, to be able to perceive the 

 relations of things in the material world, is just that kind of educa- 

 tion which this age and in fact all preceding ages have lacked. 



The perception of relations between things in the concrete is 

 the only basis on which to train the mind to compare ideas in the 

 abstract. The lack of this basis is responsible for much of the 

 loose thinking of the present day. 



If our truly heroic efforts in the line of education are to have 

 any real results, we must begin upon a sound basis, and we may 

 well rejoice at the adoption of manual training in our schools, for 

 that is the very element best fitted to bring about the desired 

 result. 



