SCIENCE. 



FRIDAY, DECEMBER 12, 1884. 



COMMENT AND CRITICISM. 



The question of manual training is begin- 

 ning to receive in this country the attention 

 it deserves. Among the indications of this 

 fact, we point to the experiments which are 

 in progress in New York, Philadelphia, St. 

 Louis, Chicago, Baltimore, and other impor- 

 tant cities ; to the admirable debate (never, 

 we believe, adequately reported) which oc- 

 curred in the section of mechanics at the 

 Philadelphia meeting of the American associa- 

 tion ; to the report presented to congress a 

 year or more ago on technical education, by 

 Gen. Eaton, the U. 8. commissioner ; to the 

 interest which has been awakened by the Brit- 

 ish-commission report on the same subject, 

 of which three volumes have appeared ; and, 

 finally, to the action of the Slater trustees in 

 insisting that the income which they distribute 

 among the schools for freedmen shall only be 

 given to schools where manual labor or handi- 

 craft is encouraged. 



Some light is thrown upon principles and 

 methods by a recent paper on technical educa- 

 tion, by David Sandeman and E. M. Dixon 

 of Glasgow. The}* discuss the relations of 

 the elementary school and the work-shop ; 

 second, the part which secondary schools may 

 take in preparing boys for industrial pursuits ; 

 third, the sphere of school work-shops or tech- 

 nical schools. Their conclusions, which are 

 of general interest, though intended only for 

 Scotland, are briefly stated, as follows: Every 

 child should have as good a general education 

 as he can get ; as circumstances differ, schools 

 must be adapted to different wants of the 

 industrial classes ; there should be elemental- 

 schools for children less than thirteen years 

 old, secondary schools for more who can con- 

 tinue to stud}' until they are sixteen ; and, in 



No. 97. — 1884. 



both, school work- shops should be established ; 

 apprenticeships might thus be reduced in time ; 

 finally, trades should be taught systematically 

 to the young, after they leave school, either in 

 a work-shop or in a special building detached 

 from a work-shop, as experience ma}- suggest. 



An argument which did good duty during 

 the dark ages, but which has fallen into disuse 

 in later times, has seldom been more naively 

 employed than in the following passage, taken 

 from a little book just published, ' On the dis- 

 covery of the periodic law : ' — 



"Are the atomic weights invariable ? This ques- 

 tion must most probably be answered in the affirma- 

 tive. If the atomic weight of an element varies, such 

 variation is most likely very slight, otherwise the 

 simple relation between the atomic weights of the 

 elements when arranged in their natural order would 

 be liable to be disturbed." 



Mr. Newlancls (late professor of chemistry 

 in the City of London college), who is the 

 author of the above passage, is also a claimant 

 to the honor of having discovered Mende- 

 lejew's periodic law. How far chemists were 

 from suspecting the truth of that law in 1866, 

 appears from the fact, that, at a meeting of the 

 Chemical society, Prof. G. F. Foster humor- 

 ously inquired of Mr. Newlands whether he 

 had ever examined the elements according to 

 the order of their initial letters. 



How much brighter is sun than moon ? Can 

 anybody tell? Has anybody tried to tell? 

 What shall be the standard of measurement ? 

 Sir William Thomson has lately printed a note 

 which conveys some curious data bearing on 

 these questions. During the meeting of the 

 British association at York in 1881. he ob- 

 served the moon when it was nearly full, and 

 at about midnight. He found the light to be 

 equal to that of a candle at a distance of two 

 hundred and thirty centimetres. Making no 

 account of the loss of moonlight in transmis- 



