DESCRIPTION OF A NE^V PADLOCIC. 4^ 



This little calculation will appear to any other perfon to be Defcription of a 

 a common account, but it is to the proprietor a memorandum ^ination.° ^'^"^' 

 by which he will perfectly recollect that the firft letter of his 

 combination is the eleventh of the alphabet, that the fecond 

 is the fourteenth, and fo of the reft. 



REMARKS. 



This padlock appears at firfl fight fimilar to that contrived 

 by Cardan ; but we know that his was not capable of having 

 its combinations changed; whence it refults that the manufac- 

 turer, the retailer, and every other perfon who may have feen 

 it opened, can themfelves open it with the fame facility as the 

 proprietor himfelf. The notches which produce the opening 

 may be alfo difcovered by the feel; our lock has falfe notches 

 cut in the centre-piece of the mechanifm which prevent the dif- 

 covery of the real one. 



Laftly, The clafp of this padlock is made of hardened and 

 tempered fleel, to prevent its being eafily cut by an ordinary 

 file. It is annealed fo far only as to prevent its breaking. 



Annotation. W. N". 



The remaining part of this paper contains the addrefs of the 

 inventor and vendor, C. Regnier, ci devant Jacobins, Rue Do' 

 miniqite, F. St. Germain d. Paris, and alfo a certificate of ho- 

 nourable mention, &c. from the Atheneedes Arts. 



The lock of Cardan conhfts of the four vifible circular parts 

 carrying the alphabet. Thefe as well as the central parts of 

 the prelent lock are perforated half way through their centers 

 by an hole, and quite through by a fmaller hole, in the fide of 

 which laft there is a notch extended to the circumference of 

 the larger hole. All the four pieces are placed upon a central 

 pin, which has fide projeftions anUvering refpeclively to the 

 notches, but occupying the fpace of the larger hole while the 

 lock is clofed. From this conftru6lion it is evident that the 

 lock cannot be opened unlefs every one of the notches be placed 

 oppofite its proje(5lion ; that this pofition or placing is fettled 

 by the maker, and not variable; and that the lock is liable to be 

 opened, though not eafily, by the tentative procefs defcribed 

 at p. 204 of our laft volume. 



Cit. Regnier has perfe6ted the lock of Cardan by making 

 the fyftem of the alphabet moveable with regard to the inter- 

 nal 



