TOL. XLIII.] PHILOSOPHICAL TRANSACTIONS. 181 



or packthread, a graduated board, and a common stone, or any other ponderous 

 body: but the drawing here added, fig. 1, pi. 4, will fully explain it. 



A represents a board, which hangs commonly against a wall, divided and figured 

 according to the size of the candle made use of.* b, a little shelf to place the 

 candle on. cc, a thread or packthread, tied fast at d, and hanging over a pulley 

 at E, to which a weight is hung at f. 



By sliding the spring of the candlestic g, up or down, as occasion requires, 

 the fiame of the candle is raised as many hours above the thread as the person 

 that adjusts it designs to lie before he is called up. At the desired hour the candle 

 burns the thread in two, the weight falls, and by its noise seldom fails to wake 

 the person. 



But if the man, who makes use of this contrivance, happens to be of a more 

 than commonly sleepy disposition, in such a case another thread is tied to that 

 part of the line cc which is next the pulley, and its other end is twisted round 

 the thumb or wrist of the sleepy person ; by which, when the candle burns the 

 line, and the weight falls, he receives such a sudden pull as can hardly fail to 

 wake him ; as the drawing will easily explain. 



If the line for a few inches on each side of the candle be wire, with a short 

 thread only just in the middle where the candle is placed, there can be no danger 

 of doing mischief by the fire running along the line. 



And thus may the poorest mechanic provide himself with a useful servant at a 

 very small expence. 



Of some Human Bones, Incrusted with Stone, now in the Villa Ludovisia at 



Rome. Communicated to the R. S. by the President, Martin Folhes, Esq. 



N°477, p-557. 



Something like the body of a petrified man being mentioned by several authors, 

 as preserved in the Villa Ludovisia at Rome, and the same having been lately re 

 ferred to in a discourse read before this Society ; he thought that a drawing o. 

 that curiosity, which he procured at Rome might possibly deserve the notice of 

 the gentlemen, especially, as it will hence appear, that the several accounts 

 hitherto given of it are not very accurate, or at the best convey but a very im- 

 perfect idea of the truth. 



The following passage occurs in the journal-book of the Society, for April 1 7, 

 1689. " Mr. Henshaw related, that he had seen, in the Villa Ludovisia at 

 Rome, the body of a man incrusted with a sort of a white marble or alabaster 

 case, supposed to have been a man frozen in the alps, and after, in long process 

 of time, this incrustation to have grown upon him ; and that one of his arms was 

 broken off, purposely to show that it was no imposition." 



• For want of such a board a common ruler is frequently used, to set the number of hours between 

 the flame of the candle and the thread. — Orig. 



