I 258 •] 



kingdom, and have prevailed on feveral of my philofophical 

 friends in different counties to keep exad regifters of the baro- 

 metcF, thermometer and rain gage. ByT,-tIief.s .means I am in- 

 duced to hope that we fliall be furniflied v/ith a part of the 

 natural hiflory of this ifland as yet little known, and which 

 will not merely be gratifying to curiofity,-; but lappli-p^able- to 

 the moft ufeful purpofes, and which promifes to fupply the 

 deficiency of obfe'rvation, and' enable the philofophcr to cori-edt 

 his theory by fads. \n-^?v;((\^ Wrv^Sl 



The barometer and thermometer are infiruments which are 

 liable to little error when carefully' made 'and ' in the ' moft 

 fimple form ; but rain gages are very imperfed inftruments. 

 My attention was direded to the methods of remedying their 

 imperfedions as much as poflible,' from having obfervcd that 

 the journals of two gentlemen at Kendal in Weftmoreland, whofe 

 .accuracy in obfervation could not be fufpedcd, diifered con- 

 '^'= •"'•I '"■-'-' fiderably, though their gages were fimilarly expofed, but I do 

 not know whether fimilar in their conftrudion. 



'''■RAiV<TAGE's'are-imperfed on two accounts. •'Firfti"iff Sctoihb 

 of the evaporation which very commonly takes place on the 

 interior furface of the fuiinel during wet weather in fummer-,- 

 for the air is for the moft part in a condition- to' abforbmonfe* 

 water than' 'it contains, though our humid atmofphere is forrie^ 

 times fo pcrfedly faturated as to depofite part'of'lts vapfturs On 

 furniture within doors, even during the months of July and 

 Ausuft, provided the weather be very wet ;' biif water "will' 

 frequently evaporate from the furfaces of many bodies, particularly 



from 



