INTRODUCTORY.
Geology is of all "hobbies" the one best calculated not only to develop the physical powers, but also, if pursued with any degree of earnestness, to train and extend the mental faculties. To study geology properly, the rocks themselves must be visited and carefully observed, their appearance noted, and the fossils, if any, which they contain, collected. This necessitates many a pleasant walk into the open country to quarries and cuttings, or rambles along the sea-shore to cliffs which may be worth investigating, whilst botany, entomology, or any other congenial pursuit, may be followed on the way; for natural science in its different branches has so many points of connection that it is impossible to study one of them without increasing one's interest in, and knowledge of, all the others. Again, in arranging, classifying, and studying at home the specimens collected on these expeditions, many an hour may be usefully spent; habits of exactitude and neatness are acquired; whilst in endeavouring to draw correct conclusions as to the way in which particular rocks were formed, and by what agencies brought to their present position, the reasoning faculties are exercised and developed.
The existence of fossil shells and bones in various strata of the earth's crust attracted attention at a very early date of the world's history; the Egyptian priests were aware of the existence of marine shells in the hills bounding the Nile valley, and from this fact Herodotus drew the conclusion that the sea formerly covered the spot. The bones of the larger mammalia (rhinoceros, elephant, etc.), were, however, thought by the ancients to be human, and hence arose the idea of a race of giants having existed at some previous period of the earth's history. It was not, however, until near the end of the last century that geology began to be recognised as a science, and the true bearing of fossils in relation to the rocks in which they were found was conclusively proved. William Smith in England, and Werner in Germany, while working independently of each other, both came to the same conclusion, viz. that the numerous strata invariably rested on each other in a certain order, and that this order was never inverted,[1] whilst William Smith in addition proved that each group of rocks, and even each stratum, had its own peculiar set of fossils, by which it might be recognised wherever it occurred. From that time forth the study of the various fossils began to be considered as a separate science apart from that of the beds containing them; this is now known as Palæontology, the study of the composition of the rocks themselves being termed Petrology.
At this moment, however, we are less concerned with the study of rocks and fossils than with the best and simplest way of collecting, preparing, and arranging specimens as a means to this study.
THE CABINET.
With regard to the cabinet for such specimens as you are able to collect, the same advice holds good as that given in a previous Manual (The Young Collector's Shell Book), namely, the simpler the cabinet the better, though of course card-board boxes would not as a rule be strong enough to stand the weight of the specimens, and hence it is advisable to have wooden ones. The boxes in which Oakey's Wellington Knife-powder is sent out (they measure about 15 in. × 10 in. × 3 in.) are on the whole the most convenient size, and are easily obtainable at any oil and colourman's. These, when painted over with Berlin Black, after first removing the external labels, look very neat. The inside may be papered according to taste, when the trays may be arranged in order ready for the reception of your specimens.[2]
[1] Except in such cases where the rocks themselves have been displaced by movements of the earth's crust.
[2] For description of trays, see "The Young Collector's Shell-Book."