In the Workshop.

Progress, Volume III, Issue 4, 1 February 1908, Page 122

In the Workshop.

The following are the principal kinds of hone and oil-stone from which a workman is likely to be able to make his selection — the order in which they are placed being approximately that of their abrading power ; those at the top of the list being the " fastest cutting," a quality which is generally accompanied by a want of fineness in the edge produced. 1. Washita Oilstone. — A very compact white sandstone, of rather recent introduction, almost resemblin g Carrara marble in appearance. Although it does not greatly differ m price from Turkey stone, its much greater uniformity and slightly more rapid cutting property cause it to be in more favour with carperters and others, with whom coarseness of edge is not an objection. 2. Turkey oilstone. — When of good quality no better substance can be employed for setting tools for which great fineness of edge is not required, since it cuts the hardest steel with avidity even when but little pressure is applied. At the same time it is of a close grain, and is not easily scratched. Unfortunately, it is a cry \ ariable in quality, as jt is also in colour ; the latter which is called white, grey, or black being generally a veined mixture of different shades of bluish and brownish grej-s. Its cost is about three times that of the stone next mentioned. 3. Charnley Forest Stone. — Found near Mount Sorrel, in Leicestershire. This is the best of the British oilstones, and has long been a favourite with carpenters and others, that from the Whittle Hill Quarries, which is of grey colour, dappled or streaked with red, being considered to be the best. Till lately this has hardly been obtainable, the only representative of Charnley Forest stone being a rather inferior one with a decidedly green tint. Both of them, however, give a very fairly fine edge, but do not cut quite so rapidly or with --xs slight pressure as Turkey. 4. Canada Oilstone. — A very fine porous sandstone of a greyish white colour, which has been recently introduced. Being much less compact than any of the preceding stones, it is much more rapidly worn away. Its first cost, is, however, rather less than that of Charnley stone. 5. Grecian Hone. — Under this name a slaty stone is imported which is of a greenish colour, and, although said to be superior to Welsh oilstone, does not greatly differ from it in appearance. 6. Welsh Oilstone. — A hardish stone of a green colour and slaty texture, inferior to the Charnley Forest for joiners' use. In price it is about the same, as also is the Grecian hone, No. 5. 7. Arkansas Oilstone. — Cuts slowly, but is very superior to all those abo\e mentioned for giving a fine edge to surgical instruments, &c. Although extremely costly — its price being about four times that of Turkey stone — it is extensively used for such purposes. In colour it resembles Washita oilstone, but it is of very much finer grain and wears away very slowly. 8. German Hone. — Thin slabs of a very soft yellow stone, cemented upon a rather harder but similar material of a slate-blue colour, are imported and sold under this name. The extreme softness of the former renders it almost useless for such edgetools'as we have been considering, although it is well adapted for setting razors, to which it imparts an edge of great smoothness and delicacy.

After Bacon long ago advocated so strongly the method of experiment and deduction for acquiring scientific knowledge, there was at first a slow, and, as time went on, an increasingly rapid, adoption of the method. The erroneous inverse method was well exemplified by the alchemists in their search for the means of transmuting the baser metals into gold. They pre-supposed it could be done, but their own experiments and observations showed the futility of their ideas. The flat-world, the caloric, and the calxphlogiston theorists were in similar case. Indeed, in nearly all instances of theories