The parish to which Bramah belonged was naturally proud of the distinction he had achieved in the world, and commemorated his life and career by a marble tablet erected by subscription to his memory, in the parish church of Silkstone. In the churchyard are found the tombstones of Joseph's father, brother, and other members of the family; and we are informed that their descendants still occupy the farm at Stainborough on which the great mechanician was born. [1] The lock invented by Bramah was patented in 1784. Mr. Bramah himself fully set forth the specific merits of the invention in his Dissertation on the Construction of Locks. In a second patent, taken out by him in 1798, he amended his first with the object of preventing the counterfeiting of keys, and suspending the office of the lock until the key was again in the possession of the owner. This he effected by enabling the owner so to alter the sliders as to render the lock inaccessible to such key if applied by any other person but himself, or until the sliders had been rearranged so as to admit of its proper action. We may mention in passing that the security of Bramah's locks depends on the doctrine of combinations, or multiplication of numbers into each other, which is known to increase in the most rapid proportion. Thus, a lock of five slides admits of 3,000 variations, while one of eight will have no less than 1,935,360 changes; in other words, that number of attempts at making a key, or at picking it, may be made before it can be opened. [2] The weight raised by a single press at the Britannia Bridge was 1144 tons. [3] Dr. Thomas Young, in his article on Bramah in the Encyclopaedia Britannica, describes the "rotative principle" as consisting in making the part which acts immediately on the water in the form of a slider, "sweeping round a cylindrical cavity, and kept in its place by means of an eccentric groove; a contrivance which was probably Bramah's own invention, but which had been before described, in a form nearly similar, by Ramelli, Canalleri, Amontons, Prince Rupert, and Dr. Hooke. [4] A Letter to the Right Hon. Sir James Eyre, Lord Chief Justice of the Common Pleas, on the subject of the cause Boulton and Watt v. Hornblower and Maberly, for Infringement on Mr. Watt's Patent for an Improvement of the Steam Engine. By Joseph Bramah, Engineer. London, 1797. [5] Sir Samuel Bentham and Marc Isambard Brunel subsequently distinguished themselves by the invention of wood-working machinery, full accounts of which will be found in the Memoirs of the former by Lady Bentham, and in the Life of the latter by Mr. Beamish. [6] "Record of the International Exhibition, 1862." Practical Mechanic's Journal, 293.