418 Ohsa'vations respecting a New Scale 



Upon this principle the pre<?ent scale is founded, which 

 T cannot help thinking is perfectly imexceptionahle, being 

 fixed on an unalterable basis ; and that in a thermometer 

 thus constriictc/i- there will be ever a coincidence in the 

 central point oV«this thermometer with that precise tem- 

 perature which is most congenial to the feelings of the 

 iunnan bodv, and prove universally and permanently a 

 Correct standard for reference, and consequently, I should 

 thiiik, render this instrument more intelligible and interest- 

 ing, and of course more extensively useful. 



With respect to the divisions, f adopted those of Fah- 

 renheit from an opinion of that being the fittest, consider- 

 ing those of Reaunuir, the centigrade, &c. as being too 

 few, and decimal divisions unnecessary in a thermometrical 

 scale. ^ 



Hence it will follow, that being placed at 62° of Fah- 

 renheit, 150^ will be the boiling, and minus 30^ the freez- 

 ing, points of water; and all other points on Fahrenheit's 

 scale may be reduced to this, by subtracting 62 for any 

 degree above of Fahrenheit's, and adding 62 for any de- 

 gree below 0. 



This thermometer may be considered as particularly ap.r 

 propriate to the purpose of regulating the heat of rooms, 

 &c. and showing the exact variations in the air from that 

 temperature which is at all times most congenial and sa- 

 lutary to the human body. 



The difficulties that may occur in the introduction of a 

 new thermometrical scale, are not more, perhaps less, than 

 in many other innovations, viz. the New Slyle — the New 

 Chemical Nomenclature, &c. 



The mechanical method of graduating this thermometer 

 is thus : the freezing and boiling poinis of water having 

 been taken in the usual v/ay, the freezing point is to be 

 marked 30, and the boiling point 150 ; this space is then to 

 be divided into six divisions, or parts =30° each, and the O 

 placed at the first division above 30, or the freezing point ; 

 the scale is then to be completed by marking in the tenths 

 above and below 0, continuing the graduation to any de- 

 sired extent. 



Sir Isaac Newton, who I believe was the person that 

 originally fixed on the freezing and boiling points of wa- 

 ter, cmijointlyy for the adjustment of a thermometrical 

 scale, places his zero at the freezing point, from a notion 

 of that being the utmost degree of cold ; and Fahi'enheit, 

 for a similar reason, placed his zero afterwards at 32 de- 

 p-rees below the freezing point, the degree of cold which 



he 



