480 
POPULAR SCIENCE REVIEW. 
Volvox globator, or the delicate striae of Pleurosigma angulatum. This is as 
it should be. The phenomena of the star-world are as accessible for obser- 
vation as those of the flora and fauna of our globe, and they certainly afford 
a wider scope for sublime thought and philosophic generalization and analysis. 
As Mr. Proctor and others have pointed out, a huge, complex, and expensive 
equatorial telescope is not essential to astronomical discovery. Keen and 
patient observation, with an apparatus of very moderate power, will do wonders 
in the way of revealing appearances before unobserved. J ust as the pursuit of 
astronomy becomes more general, so does, pari passu, the publication of 
treatises on the subject become more frequent. The three works whose 
titles we give beneath, are all excellent of their kind ; two of them are 
general handbooks, and the third is a special essay upon the stars. Professor 
Airy’s book merits the highest praise for its fulness and simplicity. It deals 
with all the more important principles of theoretical astronomy, and, what is 
more, it treats of the instruments employed in practical study, and how, 
through their use, the facts upon which the laws of the science are founded 
have been recorded. This is the sort of book which the amateur will 
highly prize. It is completely devoid of technicality, so that the most 
ordinary reader may understand it ; while it is written by one of our best 
authorities, and in a most fascinating style. Professor Airy assumes' that 
his reader is utterly ignorant of scientific terms, and explains away every 
difficulty as he goes on. His illustration of parallax is one of the happiest 
hits of popular and yet accurate explanation that we have ever seen. The 
book embraces six lectures, on the following subjects : — Apparent rotation 
of the heavens ; the equatorial ; refraction ; the transit instrument ; the 
mural circle ; mode of observing ; proof that the earth revolves ; apparent 
motion of the sun ; phenomena of an axis of rotation ; apparent motion of 
planets ; measure of distance by parallax ; different methods of finding 
parallax ; precession of the equinoxes ; lunar nutation ; aberration of light ; 
measure of the distances of stars ; velocity of light ; gravitation ; pendulum 
experiments ; proper motion of stars ; motion of solar system in space, and 
weight of the planets. This little manual is certainly the most accurate and 
lucid which has been published. 
Mr. Godfray’s treatise, though professing to be intended for schools, is, we 
fear, of too high a mathematical standard for most “academies,” and it certainly 
is not the sort of book which a general reader or amateur could take up 
with profit. As a work for students who are proceeding to their B. A. degree, 
it is unexcelled, and the number of “ examples and problems ” to be worked 
out, which are appended, must render it an invaluable companion for those 
who are “ going up ” for examination in mixed mathematics. 
Mr. Proctor’s handbook will be found very useful by those engaged 
in stellar observations. It contains three very carefully prepared maps, 
of Orion, Cassiopeia, and of Jupiter’s path across part of Sagittarius 
and Capricornus. Much of the volume is devoted to observations on 
the different methods of constructing star maps ; and here we may 
remark that the author considers the “ equidistant projection ” to be best 
adapted for maps of complete hemispheres, whilst the “ gnomonic projec- 
tion” is more suited to the preparation of popular sets of star maps. 
Appended are six tables ; one of the constellation seasons, one a catalogue of 
