Mifcellanea Curiofa. 251 



to furpafs all other performances of the like Na- 

 ture. 



'Till fuch time as the Author's prefent In di- 

 Ipofttion will give him leave to beftow freely 

 his Thoughts on this Subject: upon the Publick, 

 it is the Opinion of the Society, that fuch an 

 Account be given of this Contrivance, as may 

 render it known, and recommend it to the Ma- 

 riners ufe, for which it was principally in- 

 tended. 



The Mercurial Barometer requiring a perpen- 

 dicular Polture, and the Quicl^fjher vibrating 

 therein with great Violence upon any Agitation, 

 is therefore uncapable of being ufed at Sea (tho' 

 it hath lately been contrived to be made porta- 

 ble), fo it remain'd to find out fome other Prin- 

 ciple, wherein the Pofition of the Inftruraent 

 was not fo indifpenfably neceflary : For this, all 

 thofe that ufe the Sea are obliged to the great 

 facility Dr. Hook has always {hewn, in apply- 

 ing Philofophical Experiments to their proper 

 ufes. 



It is about forty Years fince, that the Ther- 

 mometers of Robert de Fluftibus, depending on 

 the Dilatation and Contraction of included Air 

 by Heat and Cold, have been difufed, upon 

 difcovery that the Airs preffure is unequal ; 

 that inequality mixing it felf with the Effects 

 of the warmth of the Air in that Inftrument. 

 And inftead thereof was fubftiruted the feal'd 

 Thermometer , including Spirit of Wine (firft 

 brought into England, out ot Italy, by Sir Ro- 

 bert Southwell j as a proper Standard of the 

 temper of the Air, in relation to Heat and 

 Cold ; that iEthei ial Spirit being cf all the 

 known Liquors the moll fufceptible of Dilata- 

 tion 



