Vol, XVI.] rHILOSOPHICAL TRANSACTIONS. 373 



and all beyond it is lost. So that, there being nothing left to assist the fancy 

 in estimating so great a distance, but only the intermediate objects ; where these 

 intermediates appear to the eye, as, when the sun or moon are near the horizon, 

 the distance is fancied greater, than where they appear not, as when farther 

 from it : and consequently, though both under the same or equal angles, that 

 near the horizon is fancied the greater. And this I judge to be the true reason 

 of that appearance. 



The sun's eclipse May 1st, was observed here about 4- digit ; between one and 

 two o'clock afternoon. 



Account of a Booh, viz. a Continuation of the New Digester of Bones ; its Im- 

 provements, and the Uses it has been applied to, both at Sea and Land ; with 

 some Improvements and new Uses of the Air-Pump, tried both in England and 

 Italy. By D.Papin, M.D. F.R.S. N° 187, p. 329. 

 This treatise is divided into three sections. The first contains the improve- 

 ments made by the author on the digester ; with the new uses it has been ap- 

 plied to: and he does not think that any thing better can be made for such 

 things, as must be stewed in their own juices. But for other things that must 

 be boiled with water, as pulse, gellies, &c. he gives the description of another 

 engine, which he finds to be much preferable to the former; so as that a small 

 engine of this fashion, if it holds but 6 or 7 pounds of water, will be sufficient 

 to make 1 50 pounds of gelly in 24 hours ; and will not consume above 1 1 

 pounds of charcoal. He gives also the description of an engine for distilling 

 per descensum in several degrees of rarefaction and condensation of air ; and he 

 gives an account of some experiments which he has made with this instrument ; 

 from whence it appears, that in some cases the condensation of the iir will be 

 of great advantage for a quick distillation. 



In the second section are explained the improvements made by the author, 

 on the pneumatic engine. And, by the by, he answers Mr. Bernoulli, who 

 has written something against Mr. Boyle, about the weighing of the air in a 

 bladder ; and afterwards he comes to the new uses this engine has lately been 

 apolied to. 



The third section gives account of what has been done in 2 years time, in 

 Mr. Sarrotti's academy at Venice ; which had some relation to the matter treated 

 of in this book. There may be seen several new and curious experiments about 

 matters of moment : but I shall only relate two of them, from whence the 

 reader may judge of the rest. The first is, that two equal pieces of iron were 

 put, at the same time, into two equal quantities of aquafortis, the one in vacuo, 

 and the other in the open air ; and being afterwards taken out at the same time ; 



