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Abstract

As most intending candidates for London Matriculation will be aware, the new regulations affecting the science subjects have been in force since last June. Chemistry and natural philosophy have been replaced by mechanics, which is compulsory, and chemistry, light and heat, or magnetism and electricity, at the option of the student. To meet these new requirements Dr. Aveling has prepared a series of text-books on the specified subjects, of which the book before us is one. The book is of necessity planned on examination lines; and, although the author hopes “that the matter and method may be of service in the introduction of students generally to the subjects considered,” we could hardly recommend it to those who do not require it for examination purposes. However, it completely covers the syllabus, and gives accurate, though often scanty, information. In the chapter on “Terrestrial Magnetism,” for example, some very useful data are given, but the explanations of the methods of determining them are very meagre. Thus, on p. 22 the declination com pass is described, and the explanation given for its use is simply that “the telescope is set in the plane of the geographical meridian, and, as the needle sets in the plane of the magnetic meridian, the angle between the telescope, which always lies over 0° to 180° on the circle, and the needle, is the declination.” Again, referring to the determination of dip, it is simply stated “that when the instrument is arranged with the circle in the plane of the magnetic meridian, the angle of inclination can be read off on the circle” (p. 26). We fear that very few students would succeed in getting even approximate values with only these brief statements to guide them if the instruments were put into their hands.

Magnetism and Electricity.

By Edward Aveling (London: Chapman and Hall, 1889.)