Mifcellanea Curioja. 253 



It has been obferved by fome, th^Lt in long 

 keeping this Inftrument, the Air included either 

 finds a means to efcape, or depofites fome Va- 

 pours mixc with it, or elfe for fome other caufe 

 becomes lefs Elaftick, whereby, in procefs of 

 time, it gives the height of the Mercury fome- 

 what greater than it ought ; but this, if it fhould 

 happen in fome of them, hinders not the ufeful- 

 nefs thereof, for that it may at any time very 

 eafily be corrected by Experiment, and the ri- 

 fing and falling thereof are the things chiefly 

 remarkable in it, the jufl: height being barely a 

 Curiofity. 



In thefe Parts of the World, long Experi- 

 ence has told us, that the rifing of the Mer- 

 cury forebodes fair Weather after foul, and an 

 Eafterly or Northerly Wind ; and that the fal- 

 ling thereof, on the contrary, figmfies Souther- 

 ly or Wefterly Winds, with Rain, or ftormy 

 Winds, or both ; which latter it is of much 

 more confluence to provide againft at Sea than * 

 at Land | ! and in a Storm, the Mercury begin- 

 ning to rife is a fure fign that it begins to abate, 

 as has been experienced in high Latitudes, both 

 to the Northwards and Southwards of the jE- 

 quator. 



The Form of this Inftrument is mown in the 

 Cut, by Tab. 4. Fig. i. wherein, 



A B reprefents the Spirh-Thermometer, gradua- 

 ted from o, or the freezing Point, through all 

 the poffible degrees of the Keat or Cold of the 

 Air, at leaft in thefe Climates. 



C D, is the Air-Tbermometer 9 graduated after 

 the fame manner with the like Degrees. 



EF, 



