384 



APPENDIX. 



Baume hydrometers are purely empiric, and have nothing to 

 recommend them ; it is desirable that they should be abolished, 

 but inasmuch as they are still extensively used in France and, 

 to some extent, in America, it may be advisable to give the 

 connection between their readings and true specific gravity. 



The following formulae connect together these values : 



CONVERSION OF TEMPERATURES FROM ONE THERMOMETRIC 

 SCALE TO ANOTHER. 



In this book all temperatures are stated in the Centigrade 

 scale, and it is to be regretted that the Fahrenheit thermometer 

 is still commonly employed in England. Though the relation- 

 ship between the two is comparatively simple, it is trouble- 

 some and confusing to have two scales in use. It is perhaps 



