658 
NATURE 
lines the more elementary theory of magnetism, 
permanent and induced, with a brief sketch of 
the general theory of terrestrial magnetism. 
Chapters x., xi., xii. take up respectively electric 
currents, dielectrics, and the electromagnetic 
theory of light. The exposition is clear through- 
out, and well adapted to a student reading the 
subject for the first time. At the same time it 
will probably be felt by many that the book would 
have appealed to a wider audience if the spherical 
harmonic methods mathematically developed had 
been applied to definite problems in electrical or 
magnetic distributions. The author, however, is 
quite consistent in this neglect of practical applica- 
tions; for although chapter xii, ends with the 
statement that the ratio of the electromagnetic to 
the electrostatic unit of electric charge is approxi- 
mately 3x10, it is nowhere stated that this is 
the numerical value of the velocity of light. 
(3) Mr. E. H. Smart’s “First Course in Pro- 
jective Geometry” is both well planned and well 
written. With the exception of a brief introduc- 
tion to the method of projection in space, the first 
six chapters are devoted to the plane geometry of 
triangles, quadrilaterals, and circles, in which the 
principles of correspondence and duality, harmonic 
ranges, inversion, similitude, poles and polars, are 
developed in a systematic manner. In chapter vii. 
further theorems and problems on projection are 
given, and these suffice for what the author 
regards as the main purpose of his book, namely, 
a logical, coherent discussion of the geometry of 
the conic sections. In the later chapters the prin- 
ciple of duality is freely introduced, and the book 
finishes with typical examples of reciprocation. 
Most of the chapters contain brief historic notes 
which cannot fail to interest the student. 
OUR BOOKSHELF. 
Materials and Methods in High School Agricul- 
ture. By Prof. W. G. Hummel and Bertha R. 
Hummel. Pp, xi+385+plates. (New York: 
The Macmillan Company; London: Macmillan 
and Co., Ltd., 1913.) Price 5s. 6d. net. 
In discussing the scope of their work the authors 
begin with a definition of the object of agricul- 
tural work in elementary schools and also in the 
universities. They then find that the position of 
agriculture in high schools lies intermediately 
between these two positions. The purposes of 
agricultural work in the elementary schools are 
stated to be the opening of the minds of children 
to the common phenomena of nature, the inculca- 
tion of habits of observation, and the setting up 
of higher ideals in country life, but not to make 
farmers or farm labourers. In the colleges, on 
the other hand, the work lies in the investigation 
of the more fundamental problems of agricultural 
science and practice. The high schools should 
NO. 2311, VOL. 92] 
[ FEBRUARY 12, 1914 
teach practical agriculture, educating their stu- 
dents for the actual business of the farmer; the 
course should not, however, be narrowly voca- 
tional, but should be cultural and disciplinary as 
well, and should prepare the students to be broad- 
minded and intelligent, progressive citizens. 
Considerable stress is laid upon the necessity 
for finding suitable teachers; the teacher must not 
only possess agricultural knowledge, but be able 
to impart it to others. Neither the purely scien- 
tific man nor the purely practical man has turned 
out a success, The former fails because he lacks 
the proper point of view, and knows nothing of 
practical farming conditions; the latter fails 
because he does not know the first principles of 
the subject, and is unacquainted with the scien- 
tific basis of agriculture. 
The book is full of interest, and can be cordially 
recommended to all who are engaged in the work - 
of agricultural education at schools, farm insti- 
tutes, and colleges. 
The Deciding Voice of the Monuments in Biblical 
Criticism. By Dr. M. G. Kyle. Pp. xvii+ 
320. (London: S.P.C.K., 1912.) Price 4s. 
net. 
Tue author of this work would probably not 
resent the suggestion that he writes as an advo- 
cate or partisan, rather than as an impartial 
assessor, in a long-drawn-out dispute. The field 
he surveys is a well-trodden one—the relation 
between the Bible and the monuments—and his 
attitude is that of the most traditional and con- 
servative of writers on this subject. His thesis 
throughout is to the effect that modern archzo- 
logical study has entirely disposed of the claims 
advanced on behalf of the textual criticism of — 
the Old Testament. In his view the whole work 
of the critical school is discredited, and the 
labours of Hebrew scholars for more than a 
century past, so far from resulting in a truer 
and more accurate appreciation of the Hebrew 
text, have been worse than useless. His position 
may be indicated by the fact that he maintains 
the unity of the book of Isaiah, and holds that 
the book of Daniel embodies the prophecies of 
a historic person of that name who prophesied 
in Babylon during the exile, and was written by 
him or by one of his contemporaries. It does 
not lie within the scope of this journal to follow 
the author along his controversial path. But with 
the best will in the world to be convinced, we 
cannot help feeling that he is engaged in that 
rather pathetic process of trying to put back the 
hands of the clock. We feel sure he would have 
been far more convincing had he proved himself a 
less thorough-going partisan. 
Astronomy. By Ellison Hawks. Pp. 120. 
(Manchester: Milner and Co., n.d.) Price 1s. 
net. 
In these 120 pages the author presents the subject 
of astronomy in such a way that the beginner 
will wish to carry his reading further. The style 
is elementary, clear, and chatty, and the reader 
is led on from one subject to another in a natural’ 
