YALE, Linus, inventor, born in Salisbury, New York, 4 April, 1821; died in New York city, 24 December, 1868. His ancestors were of the same family as Elihu Yale, and his father, Linus, was a successful inventor. The son devoted himself for a time to portrait-painting, but, having considerable mechanical skill and ingenuity, began in 1850 to study mechanical problems. He devised in that year a plan by which the key to locks for the protection of bankers' safes and vaults should be so constructed that, when its essential portion was doing its work within the lock, it should be at some distance removed from the key-hole through which it had entered, and at the same time isolated from the exterior of the door by a hardened steel plate, which automatically covered the key-hole behind it. This device he patented in 1851, and thereafter until his death he was a recognized authority on all matters pertaining to locks and safes. His first patent was followed by others for bankers' safes, and for bankers' flat-key and common locks. He patented in 1858 a device for adjusting at a right angle the joiners' square, in 1865 one for reversing the motion of screw-taps, and in 1868 two for improvements in mechanics' vises, and he also obtained patents abroad for certain of his inventions. In the course of his experience he became convinced of the necessity of abandoning the use of a key-hole, as it afforded an easy introduction for gunpowder or other explosive. This led to the adoption of the permanent dial and shaft as used in the so-called "combination locks," and subsequently to the perfection of the mechanism that is known as the clock lock. It is most radical invention was the double lock, which consisted in practically placing two within one case, to be operated by the same or different combinations so that the unlocking of either allowed the bolt to be withdrawn. tits improvements in locks and boxes for post-office use are of recognized utility and world-wide adoption. He was an exhibitor at the world's fairs of this and other countries, and was the recipient of gold, silver, and bronze medals as first awards at these exhibitions.