the late Captain Flinders) an unsuspected cause of error in ships reckonings. It was reserved for Mr. Barlow, by a series of most ingenious and satisfactory experiments, to discover the laws of this variation, and then to reduce his philosophical investigations to practical utility, by the invention of an apparatus of extreme simplicity, by which all mistakes in navigation arising from this source are completely avoided. The intrinsic merit of the discovery, and its peculiar value to a country ranking first among the maritime powers, have induced the Society to confer unusual marks of their approbation on Mr. Barlow. The large Gold Medal has been bestowed on Mr. Perkins, for his very ingenious and useful application of the Mercurial Level to the use of the navigator in ascertaining the Trim of a Ship, or that degree of inclination with regard to the horizon, which is requisite for the most rapid passage through the water. By means of this instrument, the navigator is enabled to adjust the angular inclination of his ship with a degree of precision wholly unknown before, and thus to make the utmost possible advantage of the wind. In a former Volume the Society have published the description of Mr. James Allan's machine for dividing the Circular Limbs of Mathematical and Astronomical Instruments. The liberal reward bestowed subsequently on the inventor by the Board of Longitude, for the unrivalled accuracy of his Engine, coinciding with the previously expressed opinion of the Society, has induced them to bestow a farther reward on the inventor, for his apparatus for cutting the Divisions. The description of this apparatus, added to that of the Dividing Circle itself in Vol. 28, completes the account of this admirable machine; and the Society regret, that the recent and untimely death of this excellent artist has deprived them of an associate whose abilities and public spirit have repeatedly entitled him to their honorary medals. The large Gold Medal, being the highest mark of the Society's approbation, has been bestowed during the last session on Henry Earle, Esq. for his Bed for Patients under Surgical Treatment, by which the temporary ease and final cure of persons suffering under the most serious accidents and constitutional derangements of the bony structure of the body, are very materially advanced. Mr. Brandt's Spring Pendulum Crutch, by which a clock is put into beat with greater precision, and in shorter time than by the common method of bending the crutch by hand, has received a Medal, and no doubt will be found useful on many occasions. Mr. Rotch's Arcograph, Mr. Rider's machine for cutting Tips for Hats, Mr. Baker's Bullet Mould, Mr. Reveley's substitution of Soap for Oil in setting Cutting Instruments, Mr. Goodwin's Spring Cross for Horses, Mr. Story's Portable Oven, and Mr. Lake's Double Door-hinge, fulfil respectively the purposes for which they were intended, and will be duly appreciated by those who may stand in need of them. The reward bestowed on Mr. Witty for his FireEscape, is in accordance with the desire which the Society have always felt to encourage to the utmost those inventions which offer even a rational probability of use under circumstances the most appalling to human nature. The attention which Dr. Wallich, Superintendent of the Botanic Garden at Calcutta, has shown to the interests of the Society of Arts, by an active correspondence with the Secretary and by the frequent transmission of seeds and other articles, demands this public acknowledgment of respect. A selection from the letters of this gentleman, containing several interesting particulars respecting the Mountain Rice of Napal, is inserted in the present Volume. Such are the contents of the Volume now offered to the acceptance of the public; and if from the perusal of the following pages any benefit should accrue to individuals, to the country, or to society at large, the object of this Institution will be fully attained. THE Society take the present opportunity of returning their Thanks to the different Public Bodies and Individuals who have honoured them with Presents during the Session, the particulars of which are noticed in the body of the Volume. Without presuming to direct in what channels the liberality of the friends to this Institution shall flow, it may be stated that such contributions as may put the Society in possession of a complete collection of the Publications of any value on the application of Mathematics to practical Mechanics, will be especially acceptable. The Society also acknowledge the receipt of the greater part of a Legacy of 500l., bequeathed to them by the late Dr. Anthony Fothergill. The legal forms, necessary to substantiate their claim and to put them in possession, have been gone through, and rendered effective by W. Tooke, Esq., Vicepresident, to whose gratuitous professional assistance the Society have on various occasions been indebted. The Society desire it to be clearly understood that, as a Body, they are not responsible for any Opinion or Representation of Facts, contained in the following Pages. IN VOLUME XXXVII. In List of Plates 13, for "Mr. Smith's Bow and Spring," read Mr. Smart's Bow and String. Page 18, line 16, for " Fig. 1," read Fig. 4. 67, 73, 6, for "Model," read Drawing. 3 and 4 from bottom, dele" each succeeding one filling up the interstices of the former." 73, 23, for "The first and second strings (figs. 6, 7), should be a violoncello third and fourth of the largest size," read The first string fig. 7, should be a violoncello fourth of the largest size i, covered by a smaller one k. The second string, fig. 6, should be a violoncello third g, covered by a smaller one h. (6 corner," read corners. 15 and 17, dele "The late". IN VOLUME XXXVIII. 6, for " figure 4," read figure 1. 8, from bottom, for " drawn," read withdrawn. 13, after "fig. 5," add, a the body of the anvil; 2, and 3, for "the radiant heat from the stove 8 from bottom, for " diameter," read circumfer ence. 10, for "outline plan," read elevation in outline. 12, for ditto read ditto. insert line 14 between lines 11 and 12. |