1 6 THE NA TURE-STUDY REVIEW W- >— jaw., 1909 



When the water heater was completed and thoroughly dis- 

 cussed, and after the various patterns had been compared and 

 criticised, the class took up the problem of converting salt water 

 into fresh water by distillation. After careful questioning, the 

 class worked out the conditions that the still must meet, and then 

 each member proceeded to construct one from flasks, corks, and 

 glass tubing. The designs were not all alike, some condensing 

 the steam in a bottle placed in a large jar of cold water, others 

 having a steam pipe passing through a jacket through which in 

 turn cold water was kept running. 



After the stills were running, the class was asked whether 

 it was cheaper to distill their own water with their own still 

 and pay for the gas used at $1.00 per 1000 cu. ft., or to buy dis- 

 tilled water from the druggist at 10 cents a gallon. They 

 reasoned that they must measure the gas consumed, and so a gas 

 meter was introduced and fully investigated. Each then in turn 

 measured the consumption of gas per hour for his own burner 

 and the amount of water distilled by his own still in the same 

 time. The results of these measurements gave widely different 

 efficiencies for the stills, and this fact lead to a comparison of the 

 more efficient with the less efficient and a discussion of the condi- 

 tions on which efficiency depend. 



Each child was required to hand in at the end of each experi- 

 ment a written report of his own work. 



POULTRY RAISING AS A SCHOOL OCCUPATION 



By W. A. BALDWIN 

 Principal of State Normal School, Hyannis, Mass. 



Ever since Comenius said "Things before words" there has 

 been a growing demand for some kind of physical activity upon 

 which to base the so-called "regular work" of the schools. At 

 first one form seemed as desirable as another. Even so wise a 

 man as Dr. E. A. Sheldon, Principal of the Oswego Normal 

 School, used to say that it mattered little about the kind of 

 work so long as it was objective. We have been gradually 

 coming to see that it does matter very much, and that the right 

 kind of work must possess the following, among other character- 

 istics, viz: 



