One of the advantages of pebble-collecting as a hobby is that it is one of the most leisurely of part-time pursuits, making little demand upon one’s patience and still less upon one’s physical energy. If the collector lives far from the coast, he must, of course, conduct his beach peregrinations within the limits of his annual seaside holiday, having made sure that the resort of his choice possesses a good shingle beach or is within very easy reach of one. If, however, he is fortunate enough to live on the coast and near to such a beach, he can make his forays when time, weather and mood are all entirely to his liking. A fine and not too windy day in winter, when he has the whole shore to himself, provides the happiest conditions for the assiduous collector. Unless he is one of those rare unfortunates who suffer from the fear of open spaces, he will agree with Byron that:
There is a rapture on the lonely shore, There is society where none intrudes, By the deep sea, and music in its roar.
The pastime commends itself on other grounds. For example, it is very inexpensive. There is no market in pebbles. They are there for the taking. Given sufficient practice, discernment and discrimination, the collector can acquire an array of choice specimens at no cost whatsoever. Naturally, he will have to pay if he wishes to have some of his collection professionally cut and polished, but he can have this done for a very modest sum. Then, again, the cult does not demand membership of any society, whose annual subscription he must pay or whose quarterly journal he feels duty-bound to read. There is no scanning of advertisement columns for bargains nor are there any pilgrimages to sale rooms.
Once he has begun to pursue the hobby he will almost certainly feel an urge to add to his knowledge of geology. In doing so, he will experience an ever-quickening and refreshing interest, not only in his pebble expeditions, but in all his walks abroad, for he will be able to read the ‘sermons in stones, books in the running brooks’, as the enthralling record of the creation of the rocks gradually unfolds itself to him.
Many geologists and mineralogists make their own collections of rock specimens, but they restrict their choice to fragments of rock that have been freshly fractured and, in consequence, have an unweathered surface. They also try to ensure that the piece they select is representative of the whole mass of rock from which they hammered it out, or, if the mass has variations, that they secure enough specimens to represent those variations.
The pebble-collector cannot adopt that procedure, as all his pebbles have acquired to some extent a disguise in the form of a ‘skin’ as the result of the rolling and weathering they have endured. They must appear in his collection as he found them. They will, of course, look all the better for a wash and brush-up, but this will not rid them of their disguise. However, he can, and should, emulate the example of the conscientious geologist in one respect: he should strive to gather two pebbles of each kind in his collection, retaining one in its beach disguise and breaking the other in order to display a fresh, unweathered surface. The two should lie side by side in his cabinet. From the broken surface of one he can learn much about the composition, texture and colouring of the rock from which it came; from the unbroken and disguised surface of the other he will be able to memorize the appearance of a beach pebble of that rock.
If the broken pebble’s texture, colour or fossilized contents are especially pleasing to him, he can, of course, acquire a third pebble of that kind and have it cut and polished.
In compiling and arranging his collection he must try to work to a plan from the outset. Here are a few suggestions :
Firstly, he can decide to make a large and comprehensive collection, fully representative of all but the very rare rocks. Only the more determined, energetic and conscientious collectors would set themselves this task, but it is an admirable objective. If he attempts it he should follow faithfully the orthodox classification of rocks, allotting separate compartments to igneous, metamorphic and sedimentary rocks, and also keeping separate the various divisions of the three main classes, e.g. the division of the igneous class into volcanic (extrusive) rocks and plutonic (intrusive) rocks. He must also display specimens of every common variety of even one kind of rock, e.g. limestone (oolitic, dolomitic or magnesian, coral, crinoidal limestone, etc.).
Secondly, if he has neither the leisure nor the desire to be so thorough, he can adopt the sound plan of making his collection as representative as possible of one good beach or of several good beaches. But here, again, he must try to classify his specimens in accordance with approved geological principles.
Thirdly, if his interest should lie wholly or mainly in one group of rocks, he may limit his collection to pebbles of those rocks and still be able to display a good assortment. Some collectors, for instance, find delight only in siliceous rocks, possibly because the members of the silica family present a glittering array, or perhaps because some of them can claim to be called semi-precious stones. Classification, in this case, is simple, as only one main mineral is involved. The sub-divisions are merely the names of the pebbles, e.g. quartz, chalcedony, agate, carnelian, jasper, etc.
Other collectors are unmoved by any rocks other than the . fossiliferous kind, as their interests are more biological than geological, or, in other words, they prefer the organic to the inorganic. It is preferable to classify a collection of this kind under the headings of the fossils themselves rather than of the rocks that contain them, as the fossils are many but the kinds of fossil-bearing rock are comparatively few, e.g. limestone, chalk, flint, chert, shale, sandstone, grit, marl and clay.
Accompanying every pebble must be a little card on which the collector has entered the name of the rock, the beach and the date of the find. If the beach is a long ridge or belt of shingle, some rough indication of the position occupied by the pebble on it should be given. The memory can be very untrustworthy if bags of pebbles are left unlabelled for even a day or two after a visit to several beaches, so, to ensure correct identification, the collector who intends to visit several beaches in the course of a day or holiday must take with him several stout paper bags and mark on each of them that he fills the name of the beach and the date. If he visits one beach only, he should mark the bag at once. Should he fail to do so and the bag is left lying about, pending a spare hour when he can add the contents to the cabinet, he will not be completely certain of the beach whence they came.
The word ‘cabinet’ has been freely used in these articles but this does not imply that ownership of a geological display cabinet is essential. Naturally, it is very desirable, but, failing it, there are other articles that will serve the purpose moderately well. Some of them can be bought at furniture sale rooms or second-hand shops, others can be made at home by collectors with an aptitude for joinery. Old filing cabinets are not to be despised; glass-fronted- cupboards, fitted with a good number of shelves, all of little depth, are excellent. A box or chest in which wooden trays lie, one above the other, each tray being divided by thin partitions into 32 or 40 compartments, will provide room for a fairly big collection; but, for the collector who likes to have his specimens on permanent view, there is nothing to equal the glass-topped, shallow showcase.