nature of stones. [Illustration: Fig. 1. Pocket Trimming-hammer.] [Illustration: Fig. 2. Duck's-head Hammer.] And now, as to the _tools_ necessary to the young geologist. First of all, he cannot take _too few_! It is a great mistake to imagine that a full set of scientific instruments makes a scientific man. The following hammers, intended for different purposes, ought to be procured. Fig. 1 is an exceedingly useful weapon, and one we commonly use, to the exclusion of all others. It is handy for breaking off fragments of rock for examination; and, if fossils be included in them, for trimming the specimens for cabinet purposes. As a rule, however, field geologists are always divided over the merits of their hammers, some preferring one shape and some another. Fig. 2 is generally used for breaking up hard rocks, for which the bevel-shaped head is peculiarly adapted. It is usually much heavier than the rest, and is seldom used except for specific purposes. If our readers are inclined to study sections of boulder clay, and wish to extract the rounded and angular boulder from its stiff matrix, they cannot do better than use a hammer like Fig. 3. This is sometimes called the "Platypus" pick. Both ends can be used, and the pick end is also good for working on soft rocks, like chalk. A little practice in the field will teach the student how to use these tools, and when, much better than we can describe on paper. The hammers can be obtained from any Scientific instrument manufacturer, or from any of the dealers in geological specimens. We have found that the best hammers for usage, however, were to be made out of an old file, softened and well welded, rolled, and then hammered into a solid mass. If properly tempered a hammer made in this fashion will last you your life. [Illustration: Fig. 3. "Platypus" Pick for clay, &c.] So much for the rougher weapons of geological strife. Next, be sure and provide yourself with _thick-soled_ shoes or boots. Geological study will take you into a good many queer places, wet and dry, rough and smooth, and it is absolutely necessary to be prepared for the worst. Patent leather boots and kid gloves are rarely worn by practical geologists. And we have heard it remarked at the British Association meetings, that they could always tell which members belonged to the Geological Section by their _thick-soled_ boots. A similar remark applies to clothes. The student need not dress for the quarry as he would for the dining room. Good, strong, serviceable material ought to be their basis.