or Hone-Slate.** These are various slaty-stones wrought into the form of straight slabs, and used for whetting or sharpening the edges of tools after they have been ground. They consist chiefly of the following:—1. Norway rag-stone, the coarsest variety of the hone-slates; it gives a finer edge than the sandstones. 2. Charlestown Forest stone, which is used as a substitute for Turkey oil-stone. 3. Ayr stone, Scotch stone, or slate stone, used for polishing marble, and copper plates, but the harder kinds for whetstones. 4. Idicall, or Welsh oil-stone, used for small articles of cutlery. 5. Devonshire oil-stone, for sharpening thin-edged broad tools. 6. Cutlers' green-stone, from Snowdon, which is very hard and close, and is used for giving the last edge to lancets, &c. 7. German razor-hone, used almost entirely for razors. It is obtained from the slate mountains near Ratisbon, where it forms a yellow vein in the blue slate. It is sawn into thin slabs, and cemented to a slab of slate which serves as a support. 8. Blue polishing stone, a dark slate of uniform texture, used by workers in silver and some other metals, for polishing off the work. 9. Gray polishing-stone, somewhat coarser than the blue. 10. Welsh clearing-stone, a soft variety of hone-stone used by curriers for giving a fine edge to their broad knives. 11. Peruvian hone, for sharpening large tools. 12. Arkansas stone, from North America. 13. Bohemian stones—used by jewellers.

Turkey oil-stone is superior to every other substance as a whetstone; it will abrade the hardest steel, and is sufficiently compact to resist the pressure required for sharpening a graver. The black variety is somewhat harder than the white. These stones are imported from Turkey in irregular masses, seldom exceeding three inches square, and ten inches long, and are cut up by means of the lapidary's splitting-mill, and diamond powder, then rubbed smooth with sand or emery on an iron plate, inlaid in wood, and secured by glazier's putty. Sperm or neat's foot oil, or some oil which does not readily thicken, should be used with them. Oil-stone powder is used for grinding together the brass or gun-metal fittings of mathematical instruments, and also instead of pumice-stone for polishing superior brass-work.

The following analyses throw an interesting light on the nature of polishing stones:

| Polishing stone | Abrasives | Slides | Lines | Iron | Water | Sand | Add. | |----------------|----------|--------|-------|------|-------|------|------| | Pollishing slate | 4-0 | 83-5 | 8-5 | 1-6 | 9-0 | ... | ... | | Do. do. | 7-0 | 66-5 | 1-25 | 2-5 | 19-0 | 1-5 | ... | | Bohemian stone | 1-0 | 79-0 | 1-0 | 4-0 | 14-0 | ... | ... | | Turkey hone... | 3-33 | 72-0 | 13-33 | ... | ... | ... | 10-33 |

(H.C.T.)

WILLIAM,** the author of the Year Book, Every-Day Book, &c., was the son of a dissenting minister of Bath, where he was born in 1780. Abandoning the law, to which he was originally trained, he began business as a bookseller and publisher, and acquired a great name by his vindication of popular rights in a newspaper which he edited under the title of the Reformist Register. His popu- larity was greatly extended by his famous series of political satires called *The Political House that Jack built*, which ran through upwards of fifty editions, and contributed greatly to bring into disrepute the government of the day. Encouraged by his success, he next published a series of parodies of the liturgy, also directed against the ruling powers, who determined to prosecute him for blasphemy. His defence, which lasted for three days, was conducted by himself with a courage, temper, and ability that recalled the days of Horne Tooke, and resulted in a triumphant acquittal. His subsequent publications of the *Every-Day Book*, &c., forming a kind of calendar of popular English amusements, sports, pastimes, ceremonies, manners, customs, and events incident to every day in the year, though they rendered good service to an important department of literature, involved him in debt, and at last landed him in jail, where he remained for some time. Released by the kindness of some friends, he opened the Grasshopper Coffee-house; and to eke out his scanty means, published his *Year-Book*, which was equally unfortunate with its predecessor. Towards the close of his life a complete change took place in his religious views; and from having been a scoffer, and as nearly an atheist as a man can be, he became a humble and anxious Christian. One result of this change was his appointment to the sub-editorship of the *Patriot* newspaper, which office he held till his death in 1842. After his death his collection of pamphlets, believed to be the best private collection then extant in England, was sold and dispersed. An interesting account of his conversion was published in London in 1853.