LIST OF PLATES IN VOL. XL. 1. 2. Messrs. Cowley and Staines' instruments employed in the culture of the White Poppy, and the extraction of Opium. Mr. Marshall's Blocks for Calico-printers. Mr. Pering's Iron Gun-carriage. 1 Mr. Biddle's Hay-borer. 3. ...Mr. Richards's Draw-boy. 10. 11. 12. 18. 14. Mr. Millikin's Bistoury. JMr. Watson's system of Musical Notation for the use of the Blind. Mr. Thom's Self-acting Hydraulic Apparatus for regulating the supply of Water to Mills, &c. 15. ...Mr. Busby's Hydraulic Orrery. 16. ...Mr. Wynn's Hammer for a Turret Clock. 17. f Mr. Bowler's Rat Trap. Mr. Baker's Gun-lock. 18. ...Mr. Hookey's Coffer for repairing Ships Afloat. 19. ...Mr. Hall's Steam-engine-Boiler. 20. 21. ♫ Mr. Wigzell's Sliding-rule for marking a Ship's place Mr. Bailey's method of Opening and Shutting Church 22....Mr. Savage's Watch Escapement. 23. 24. Mr. Abraham's Magnetic Guard for Persons employed in Dry-grinding. Mr. Ainger's Hydrometer. Diagram explaining Mr. Rotch's Arcograph. PREFACE. THE Committee of Correspondence and Papers to whom the Publication of the Society's Transactions is entrusted, submit to the Society, and to the public at large, a general Summary of the contents of the present Volume. The class of Agriculture and Rural Economy contains four Communications; one of which, by Messrs. Cowley and Staines, has obtained the Large Gold Medal, being the Premium offered for the ascertainment of certain important points of practice in Turnip Husbandry. These Gentlemen have drawn a crop of full-grown Turnips sufficiently early in the Winter to admit of the Land being prepared for a crop of Wheat; which Turnips being stacked, were preserved in a sound state fit for feeding cattle to the end of April in the following Spring. Two circumstances appear to have contributed to the successful preservation of the Turnips, namely, the state of dryness in which they were kept, but principally the great care that was taken to wound the roots as little as possible, and especially, in topping the Turnips, to avoid any injury to the buds of the crown. An interesting Communication from the same Gentlemen contains the particulars of their cultivation of the White Poppy, and of their obtaining therefrom, 60lbs. of excellent Opium. J. Peart, esq. has gained a Gold Medal, for reclaiming Waste Moor Land, by converting it to permanent Pasture: the process, though expensive, has upon the whole succeeded, and is applicable to many thousand acres of rough mountainous land similarly situated. Mr. Biddle's description of a cheap, simple, and effectual instrument for boring haystacks, in order to ventilate them when in danger of firing, or for the purpose of drawing a sample, in order to ascertain the quality of the Hay, will no doubt be duly appreciated, both by the growers and purchasers of this important article. The class of Polite Arts contains a communication from Mr. Lupton, on the application of the art of Mezzotinto Engraving to plates of soft steel, instead of copper as heretofore practised. The capricious uncertainty in the number of copies which a copper mezzotinto plate will furnish, has always prevented the extension of this branch of Art, notwithstanding its many advantages in point of expedition, economy, and picturesque effect. This objection is completely avoided by working on steel, and the additional labour is far more than compensated by the increased number of copies which such a plate will afford, when compared with even the most successfully executed copper one. The class of Chemistry and Mineralogy includes two Communications. One of these by Mr. H. W. Reveley, on the Mill-Stones at present made use of in Tuscany, is interesting on two accounts; first, the superior method of dressing the Stones which it points out, which is applicable to Mill-Stones of all kinds; and secondly, as making known two materials employed in that country in preparing the finest Wheat Flour, which materials, although abundant in this Island, have hitherto served no useful purpose whatever, except as materials for roads. The second Communication is from J. Meigh, esq., on the discovery of a cheap and effectual glaze for the common coarse red Earthenware, by which not only the solidity of the ware is greatly increased, but the hitherto presumed necessity of employing vitrified lead, as the material of the glaze is wholly avoided. The direful effects of the poison of lead manifested by severe |