gg Transactions of the American Institute. 



or removal of the spindle, if such a thing be possible, does not 

 give access to the lock. 5. That owing to the duplex system of 

 locks acting upon the same bolt in such a manner that the unlock- 

 ing of either will permit the bolt to be retracted, the difficulties 

 often arising from locks getting out of order and thus preventing 

 the opening of doors by authorized persons are entirely obviated. 



The locks hereafter enumerated are also worthy of notice. 



First. The Double Treasury Vault Lock, No. 688, it having, 

 although a key lock, the advantages set forth under the first and 

 fifth heads as above. 



Second. The deed box, or safe compartment, or cash drawer lock, 

 Improved Bramah, No. 688. This lock has all the advantages of 

 the well known Bramah lock, and in addition thereto the quality 

 of being unpickable by any means known to the judges. The 

 devices by means of which this great desideratum is efiected are 

 simple in the extreme, and not liable to derangement; they, more- 

 over, add but little to the cost of the lock. This lock, it is 

 believed, will supply a w^ant which has long been felt, and which, 

 up to the present time, has not been satisfied. 



Third. The Safe Lock, No. 486. (Joseph Corbett.) The judges 

 are not certain that this lock cannot be picked by well known 

 methods, but think that the improvements aiming to prevent false 

 registry as a means of picking, and preventing inspection of the 

 register while the lock is being locked or unlocked, except by the 

 person operating it, are ingenious; and that the latter improve- 

 ment is a valuable adjunct to register loclcs used by careless 

 persons, or those not always upon their guard against felonious 



attempts to open them. 



HENRY B. RENWICK, ) 

 SAMUEL HAMMOND, ] ^''' 



Department III. 



FOURTH GROUP. 

 SEWENG MACHINES, ETC. 



To the Board of Managers: 



Gentlemen — The undersigned judges in Department III, Group 

 4, report that they have carefully examined the. several articles 

 referred to them. Taken collectively, these specimens of skill and 

 ingenuity furnish evidence of continued advance and improvement 



