318 BOOK NOTICES. 



DENSITY OF POPULATION AND HEALTH. 



At a general conference of British architects, a few weeks ago, the general 

 building regulations of the United Kingdom were discussed at length. Among 

 the points brought out were these: i. That the experience of what are called 

 model lodging houses, such as the Peabody buildings in London and other large 

 towns, combined with that of barracks, workhouses, and schools, furnishes 

 abundant evidence that what is termed density of population is not so detri- 

 mental physically as has been hastily assumed ; because in such buildings as are 

 referred to the rate of mortality is much less, with a density of 1,500 persons to 

 the acre, than it is in ordinary small houses, with a density of only 250 to the 

 acre. 2. That the health of a community is much more dependent upon food, 

 clothing and personal habits than upon the arrangement and construction of 

 dwellings or workshops ; for however perfect may be the arrangement and con- 

 struction, they may be entirely neutralized if the food is bad, the clothing de- 

 ficient, and the personal habits filthy. 



The unsanitary conditions of densely populated districts in this city seems 

 to be chiefly due to the fact that the houses of the inhabitants were not originally 

 intended for those who have come to live in them. — Scientific American. 



BOOK NOTICES. 



A Course in Arithmetic. A treatise in three parts, complete in one volume. 



By F. W. Bardwell, Professor of Astronomy in the University of Kansas. 



12 mo.; pp. 154. G. P. Putnam's Sons, New York. For sale by M. H. 



Dickinson, $1.25. 



The necessity for a new treatise on Arithmetic, and the advantages of this 

 treatise over some others, are pointed out by Professor Bardwell so modestly, and 

 at the same time so clearly, that we cannot do better than quote his own lan- 

 guage: "First, it is intended to present, in the compass of a single volume, a 

 complete treatise, and, indeed, all that the average pupil needs to study on the 

 subject from first to last. Secondly, the subject matter is arranged in three parts, 

 logically distinct, in each of which the pupil gives his attention to a specific 

 object complete in itself. The first part comprises the simple operations ; the 

 second, an explanation of the various measures in use, including the metric sys- 

 tem ; the third, the various applications of numerical computation to practical 

 questions. A third marked feature is found in the character of the definitions 

 and of the expositions of principles. The treatment of each topic is lucid and 

 logical, and, at the same time, in harmony with rigorous scientific accuracy." 

 One point, in which we especially agree with the author, with whom "the con- 

 viction has been reached only with deliberation and after long experience and 

 observation," is that much time has been wasted in so-called Arithmetical drill, i. e., 

 in "mental" or "intellectual" exercises. A practical improvement that we 

 notice as peculiar to Professor Bardwell, is giving the definitions and rules in the 



