INSTRUCTION in practical physics is steadily, though very slowly, gaining ground in our schools and colleges. The tardy recognition of the great importance of this kind of work is doubtless due to the fact that practical physics does not bear directly on industrial and commercial pursuits. But, for training the mind, there is no better means than a course of physical laboratory practice. The hand is exercised in delicacy of manipulation; the eye is led to perceive instead of seeing things vacantly; and the mind is trained to make scientific deductions from observed facts. Whether a boy is designed to be a politician or a preacher, whether it is intended that he should follow the law or be sacrificed to science, in fact, no matter what the calling or profession in which he has to work his way through life, by far the best mode of obtaining the accuracy of observation and deduction desirable in everyone, is through instruction in practical physics. It is because we believe this, that we welcome any indication of the extension of such knowledge. Mr. Woollcombe is the author of a little book on practical work in heat, which we were able to commend when it appeared. The present volume deserves the same praise that we gave the previous one. It begins with descriptions of such instruments as the linear vernier, sliding callipers, micrometer screw gauge, and balance, and passes on to the measurement of length, area, and volume. The experiments performed under these heads lead naturally to the determination of the densities of solids, liquids, and gases, and then to Boyle's Law, the barometer, and capillarity. This order is practically the same as that followed in “A First Course of Physical Laboratory Practice,” by Prof. A. M. Worthington, F.R.S., published eight years ago. Indeed, Mr. Woollcombe's book reminds us of Prof. Worthington's in more than one respect; but a similarity of gradation and general treatment almost inevitably exists between books covering the same ground.