DESCRIPTION OE AN ANCIENT LOCK. 203 



ledged. I will now conclude with an attempt to anfwer your 

 objection, from the bodies being in a ftate of ignition when 

 they fall to the earth. As the fpace between the earth and 

 moon muft be either nearly, or altogether a vacuum, it rouft 

 be almoft, if not quite, a non-conduclor of heat ; fo that it 

 may eafily be conceived, that a body paffing through it, may 

 retain during its patfage of about four or five days, nearly 

 the fame degree of heat with which it fet out, efpecially as no 

 change of texture takes place, by which its heat can become 

 latent. 



I remain, 



Your's, &c. 

 Cambridge, May, 2Uh, 1803. , J. B. 



P. S. For the principles of the estimations, which I have 

 made of the refinance of the atmofphere. See Alzuood on 

 Recldinear Motion, fed. 5th. 



Defcription of an Ancient Lock of Combination. W. N. 



1 HE lock delineated in Plate IX. is fixed in the lid of an Secret lock of 

 old brafs money box for the pocket ; from which Mr. Lathamof an old money 

 King Street, Soho, who deals in articles of curiofity, permitted 

 me to make a drawing. 



Fig. 1. is a perfpeclive view of the box, which meafures Defcription and 

 about three inches in diameter. Fig. 2. fhews the outfide of drawin 8' 

 the lid, at one edge of which is a hinge, and upon the outfide 

 are figures of the fun, the moon, and two clock faces with 

 hands. The figure of the moon can be Aided nearer or farther 

 from the center, and carries a bolt placed within the lid. The 

 other three parts, namely, the fun and the hands of the clock, 

 can be moved round their center pieces, and left in any 

 fituation at pleafure. Fig. 3. (hews the infideof the lid. The 

 bolt which is moveable along by means of the figure of the 

 moon, is here feen with three tails, pointing to three 

 circular pieces, in each of which pieces there is a notch to re- 

 ceive its correspondent tail. Thefe pieces move round by 

 means of the three parts on the other fide, and it will thence be 

 eafily underftood tljat the bolt cannot be Hided back, nor the 



box 



