Direct the index M to the star, so as to be seen through the sights P, O; then laying hold of the scale L, to keep it in that position, turn the cone till the star on the projection is cut by the scale, when the day of the month on the circle at the bottom of the cone will coincide with the hour and minute on the circle E F G.
This instrument, though not capable of extreme accuracy, might, by means of careful workmanship, and the addition of a small telescope, be made sufficiently so for finding stars in the day time; but such a one as that now described will answer all the purposes of a learner, and enable very young people to acquire a correct and extensive knowledge of the stars in a very short time.
The surface of a cone has been adopted for the projection, in preference to that of a globe or planisphere, having been found, after repeated trials, the figure best suited to the nature of the instrument.
An Introduction to the Comparative Anatomy of Animals, compiled with constant reference to Physiology, and elucidated by twenty copper-plates. By C. J. Carus, M.D., &c. Translated from the German, by R. T. Gore, Member of the Royal College of Surgeons in London. [◊]
IF we except Sir Everard Home’s splendid work on comparative anatomy, we have no original treatise on that subject which deserves notice; and even Sir Everard’s lectures must rather be considered as a series of essays on detached parts of that branch of science, than as a regular and systematic view of it. We have long been acquainted with the work of Dr. Carus, and have always considered it as a laborious and accurate epitome of the principal facts and authorities in the study to which it relates. From the immense field of inquiry which it embraces, it is necessarily complicated, and [p378] in some places a little obscure, but it is entirely free from those speculative and hypothetical wanderings which are too characteristic of the German school of physiology; and though it contains some systematic notions in which we cannot acquiesce, and a few new words, not the most harmonious in the world, it may very safely and properly be recommended to the student as a text-book, and to the proficient as a work of reference. The plates by which it is illustrated are upon an economical scale, sometimes rather too small to be distinct, but they are otherwise accurate and carefully drawn; and we are aware that it is impossible to obviate these objections without incurring such expense as would probably render the work inaccessible to those readers for whom it is principally compiled.
Mr. Gore has assiduously and faithfully executed the difficult task of translation, and has added no inconsiderable quantity of new and important matter in the form of notes, rendering the English work more complete, and upon many points much more satisfactory than the original.
Experiments to determine the Comparative Value of the principal varieties of Fuel used in the United States, and also in Europe, and on the ordinary Apparatus used for their Combustion. By Marcus Bull. Philadelphia and London, 1827. [◊]
THE population of London and its immediate environs may be estimated at about two millions, and the annual consumption of coals within the same district does not fall far short of two millions of chaldrons, or seventy-two millions of bushels. Of this prodigious quantity of inflammable matter, a very considerable portion escapes combustion, and lodges in the form of soot in our chimneys, or is vomited forth to contaminate and cloud the atmosphere of the metropolis: so great is this loss, that independent of the mere advantage of getting rid of smoke, its prevention is an important economical problem; and though the rage for smoke-burning has passed over, we are quite certain that the subject still deserves the most serious attention, being convinced that, of the fuel consumed in the ordinary processes of warming our houses and cooking food, at least one-third is uselessly thrown away, and might be saved by a more economical and scientific construction of common grates and fire-places. All useful and well-conducted experiments, therefore, in [p379] relation to these matters, deserve notice; and though much of Mr. Bull’s essay is not applicable to our case, it contains a variety of interesting facts and information: his experiments appear to have been very carefully conducted, and should be consulted by all those who are engaged in similar investigations.
Meteorological Essays and Observations. By J. Frederic Daniell, Esq., F.R.S. Second Part, 1827. [◊]
WE hope to be able in our next Number to enter into a detailed examination of the subject of Mr. Daniell’s inquiries; at present, therefore, our object is merely to announce the second edition of his valuable and laborious essays, and the publication of the present second part, in which, for the convenience of those who possess the former edition, all the new matter is collected. It includes the following essays:—