Royal Institution of Great Britain, 213 



him in conjunction with wards to the security of a lock, for which 

 he obtained a patent in 1774. The same principle was afterwards 

 adopted by Mr. Bramah, without the assistance of wards or ob- 

 stacles to the key, but the mode of application was very different 

 from the Eg'y])tian. In the latter, the security arose from a con- 

 cealment of the number and position of the impediments ; in Mr. 

 Bramah's, these were discoverable on inspection, and the security 

 depended on the various degrees of motion which the several impe- 

 diments required before the bolt could be moved. 



These gradual improvements induced a corresponding attention 

 to the art of picking, which would have been fatal to the reputation 

 of the new locks, but for the almost simultaneous invention of a 

 very simple and costless alteration, by which the required position 

 of the impediments is rendered utterly undiscoverable. 



There are a few contrivances which do not come within either of 

 these classes: such as the detectors, which give notice of any attempt 

 to introduce a false instrument, and the sliding curtain of Mr. 

 Lawson, by which the key-hole is so perfectly closed, during the act 

 of unlocking, that it would be impossible to move the bolt while a 

 pick remained in the aperture. 



Locks have also been made which required that the key should be 

 a powerful magnet ; others in which an unusual and complicated 

 motion must be given to the key ; others in which an improper key 

 or instrument would fire a pistol or ring an alarum. 



These expedients are, however, more curious than useful. There 

 is no difficulty in making a lock perfectly inviolable, and nearly all 

 those of any estimation now before the public are, when well made, 

 quite secure. 



Models and diagrams illustrating the two principles or means of 

 security, as also of the methods of picking, together with specimens 

 and models of the Egyptian and nearly all the modern locks, were 

 exhibited in the Lecture Room. 



It was stated, in the course of the evening, by Mr. Trevelyan, a 

 gentleman of Cornwall, that a lock, resembling the Egyptian, is 

 used in that county ; that he has also seen it in the Faro Islands, to 

 both which places it was probably taken by the Phoenicians. 



A specimen of a fungus, separated by Mr. Trevelyan from a beech 

 tree, was laid upon the table. The whole of its upper surface was 

 covered by a layer of brown resinous matter, which extended also a 

 little way round the edge over the under surface. When separated 

 by a knife and examined, it was found to be combustible, with 



