APPARATUS-MAKING IN EDUCATION. 



347 



ICCO, 



ii A 





2b 



ing to a suggestion found in Gage's Elements of Physics, illus- 

 trated well the advantage of requiring pupils to make apparatus, 

 even when free access is had to that made by the instrument- 

 maker. A piece of wood cut from the spoke of an old wheel was 

 loaded at one end with lead, so as to make it stand upright. It 

 was immersed in rain-water, and the water-level on it marked 

 1,000. By means of a Baumd's hydrometer the level of 900 was 

 found, and distances, equal to the distance between the two marks, 

 laid off above and below. Much to the boy's surprise, the hy- 

 drometer thus graduated would by no means coincide with his 

 Baume'. He attributed the error to the absorp- 

 tion of the fluids by the wood, and set to work 

 to make another, taking care this time to rub the 

 wood with beeswax, to render it impervious to 

 liquids ; but his second graduation was hardly 

 more satisfactory than the first. He then put 

 on a piece of cork for a float, the wood having 

 failed to keep an upright position in all liquids, 

 and graduated his hydrometer by means of dif- 

 ferent liquids whose densities had been found 

 with the Baume* hydrometer, and at last discov- 

 ered that the divisions were not equal. This piece 

 of work, represented in Fig. 2, consumed all the 

 boy's afternoons for a week ; but I saw the effect 

 of it in increased carefulness, and consequently 

 greater accuracy in his subsequent work, and, 

 what was still more important, in increased 

 thoughtfulness. 



A condenser for use in distilling water was 

 made after the pattern of Liebig's. The outside 

 tube was made by boring a round piece of wood, 

 ten inches long and two inches in diameter, 

 through with an inch auger. The inside tube, 

 and those for entrance of cold water and exit of 

 hot water, were made of reeds. A bottle served 

 for the still, and the whole was supported on a 

 neat wooden stand. 



Such work undoubtedly requires much energy 

 on the part of the teacher, for his suggestions JSiLcJcsIiot 

 will be needed and asked for many times during fig. 2.— htdbombtek. 

 the week. But if he is a mere college or high- 

 school graduate who has gained his knowledge of science from 

 the lectures and experiments of the professor, he will find this 

 work of making home-made apparatus even more beneficial to 

 himself than it is to the pupils. He will by means of it have 

 much light thrown upon obscure places, and will accordingly 



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