LOCK 



3474 



LOCKE 



leads her to the door, lifts her on his horse and 

 carries her away, all with her consent: 



One touch to her hand, and one word in her ear, 

 When they reached the hall-door and the charger 



was near. 



So light to the croupe the fair lady he swung, 

 So light to the saddle before her he sprung! 

 "She is won ! we are gone, over bank, bush and 



scaur ! 

 They'll have fleet steeds that follow !" quoth 



young Lochinvar. 



LOCK, a fastening opened with a key or by 

 mechanism easily kept secret, is a device as old 

 as history, for the most successful modern door 

 lock is a development of an old Egyptian de- 

 vice. It is almost impossible to open a good 

 modern night latch without the proper key, 

 and a time lock cannot be opened dishonestly 

 even by those who know its exact construction. 



When the key in an ordinary door or drawer 

 lock is turned, the cuts in the former pass over 

 wards, which are projections on the inside of 

 the lock which will stop any key npt having 

 the same cuts. But by cutting away most of a 

 key-blade, a skeleton key can be made which 

 will open nearly any common lock. 



Yale Lock. In 1860 Linus Yale, Jr., invented 

 a lock now widely used, which cannot be 

 opened with a skeleton. It is a cylinder within 

 a cylinder. In the diagram, to turn the cam 

 (c) which draws the bolt, the inner cylinder 

 must be revolved. 

 When the key is 

 not in the lock 

 the little pins 

 (p), pressed down 

 by the springs 

 above them, hold 

 the inner cylinder 

 fast. Each pin is 

 in two pieces, and 

 the division is at 



a different height MECHANISM OF A 



in each; when MODERN LOCK 



the proper key is Explanation of the figure is 

 inserted the pins siven in the article ' 

 are raised, so their divisions are exactly level 

 with the division between the inner and outer 

 cylinders. If a key differs ^o of an inch from 

 the true key beneath any one of the pins, the 

 cylinder cannot be turned. 



Combination and Time Locks. Because any 

 lock having a keyhole can be picked by an 

 expert, combination locks are used on safes. 

 These are opened by a knob which must be 

 turned back and forth certain distances known 

 only to the proper persons. But as the com- 



bination can be learned by others, or may be 

 stolen, time locks have been devised which can- 

 not be opened even by their owners except at 

 certain hours. In spite of the obvious advan- 

 tages of time locks, they are little used outside 

 of the United States and Canada. 



LOCK, in canal construction. See CANAL. 



LOCKE, lock, DAVID Ross (1833-1888), an 

 American humorist and satirist, born in New 

 York City, better known by his pen name, PE- 

 TROLEUM VESUVIUS NASBY. He first attracted 

 attention through his "Nasby" letters, printed 

 in the Findlay (O.) Jeffersonian in 1860, and 

 later in the Toledo Blade. These epistles, 

 which were supposed to be written by an un- 

 lettered man who regarded whisky and slavery 

 with equal affection, were influential in molding 

 popular opinion, since they upheld the policy 

 of the Lincoln administration throughout the 

 war. His book The Struggles Social, Finan- 

 cial and Political oj P. V. Nasby contains the 

 best of his humorous works. 



LOCKE, JOHN (1632-1704), sometimes 

 styled the "intellectual ruler of the eighteenth 

 century," was one of the most influential of 

 English philosophers. He was a native of 

 Wrington, in Somersetshire, and was educated 

 at Westminster School and Christ Church Col- 

 lege, Oxford. After his graduation he took up 

 the study of medicine. Under the patronage of 

 the Earl of Shaftesbury, whose physician he be- 

 came in 1666, he held various public offices, and 

 in 1683 followed the earl to Holland, whither 

 the latter had fled to escape arrest on the 

 charge of high treason. In 1689 he returned 

 to England and in the following year published 

 his epoch-making work, Essay Concerning Hu- 

 man Understanding. 



In setting forth his system of philosophy, 

 Locke undertook to answer the question, How 

 do we come by our knowledge, and what are 

 its limits? He was the first to speak of the 

 "association of ideas," and took the stand that 

 whatever any man can know, or reasonably be- 

 lieve in, or even conceive, is dependent upon 

 human experience. He maintained that at 

 birth the mind is as a tablet of blank paper 

 whereon Experience is to write ideas. We may 

 have ideas without having knowledge, but we 

 cannot have knowledge, or even opinion, with- 

 out having ideas, for "having ideas" means 

 "speaking intelligibly." He believed educa- 

 tion should have as its aim the development of 

 "a sound mind in a sound body." These and 

 other inquiries into the nature and limits of 

 human thought processes and education are 





