Aueust 11, 1899. ] 
who is unacquainted with Helmholtz’s modes 
of thought will find it well worth the effort 
essential to master the connected exposition 
here given of the comprehensive methods of 
d’Alembert, Lagrange and Hamilton. Many 
readers will encounter a difficulty in an unusual 
and, apparently, an unhappy notation, consid- 
ering the precedents set long ago by Lagrange. 
Those to whom English is the mother tongue 
will also be pained at the ease with which the 
old and the new terminologies are mixed. But 
these are minor matters in comparison with 
the clear physical concepts and the penetrating 
analytical processes which characterize the 
work of the great author. This last part, 
which comprises a little more than one-fourth 
of the bulk of the book, is divided into four 
chapters. The first of these treats of statics 
from the point of view of virtual displacements 
and as the vanishing case of kinetics. The 
second treats of kinetics, giving especial atten- 
tion to the equations of d’Alembert, Lagrange 
and Hamilton, the author’s well known prefer- 
ence being expressed for the Hamiltonian form 
of equation. The third chapter deals with the 
applications furnished by rigid bodies, including 
the theory of the top and the theory of terrestrial 
precession in their elements. The last chapter 
is devoted to the application of dynamical 
principles to non-conservative systems. It is 
especially noteworthy for certain reciprocal re- 
lations (Reciprocitatsgesetze) shown to hold be- 
tween pairs of partial derivatives of the external 
forces with respect to the corresponding veloci- 
ties and accelerations, several important phys. 
ical applications of these relations being cited. 
R. S. W. 
Social Phases of Education in the School and the 
Home. By SAMUEL T. DuTTON, Superintend- 
ent of Schools, Brookline, Mass. New York, 
The Macmillan Company. Pp. viii+259. 
Price, $1.25. 
This volume consists of ‘‘ lectures given dur- 
ing the past two yearsat Harvard, Chicago and 
Boston Universities, and papers read before the 
American Social Science and the National Edu- 
cational Associations.’’? The author says that 
‘the point of view isin all cases social rather 
than scholastic, and the ideas emphasized are 
SCIENCE. 183 
as worthy of consideration by parents as by 
teachers.’’ Indeed, the chief value of the book 
is that it gives a popular interpretation of some 
current ideas in educational thought. Teachers 
of all grades will find it helpful and stimu- 
lating, and there is enough sound educational 
theory at the bottom to make it a safe guide to 
parents. 
Mr. Dutton takes as his thesis the idea that 
the school is a form of social life. Its purpose 
is to minister to the support of the home and to 
render service to human society, or to socialize 
the youth and to fit him to take his place in 
society and to render the best service of which 
he is capable. In the thought that ‘‘the 
object of the school is to socialize the child, 
to make him acquainted with his environ- 
ment and conscious of his obligations to 
others,’? is to be found the elue to Mr. 
Dutton’s educational practice. He believes 
in emphasizing the ‘preparation for vocation’ 
as an aim of the school, because he believes in 
work—that ‘useful activity’ which best con- 
serves ‘man’s physical, moral and spiritnal 
welfare.’ He believes in ‘ general culture,’ the 
kind that fits one to live more efficiently and 
helpfully day by day, the kind that makes one 
a better man or woman and renders one more 
serviceable. With this idea in mind he looks 
upon the old school curriculum as meagre and 
narrowing ; he advocates more of physical and 
manual training and of the domestic and fine 
arts, ‘‘not only because they touch the ele- 
mental wants of mankind, but because they 
connect the school and the home, create a close 
sympathy between parents, teachers and pupils, 
and tend to level up whole communities where 
the less fortunate reside.’? As for other studies 
the criterion of excellence must always be the 
part they play in human life and the service 
they render to society. ‘This social aim even 
determines the methods to be employed in 
teaching—‘‘ the governing principle of the reci- 
tation should be, not competition, but coopera- 
tion ;’’ it should enter into the home life and 
the management of children in school—‘‘ thus, 
every pupil becomes actively interested not 
only in being courteous, orderly and helpful 
himself, but in haying his associates combine 
with him in this social effort.’ For this reason 
