OF METEOEOLOGICAL INSTRUMENTS. 



47 



FIG. 188. 



FIG. 182. 



FIG. 185. 



189. Plantation or Farm Barometer . 



190. PLANTATION OB FAEM BAEOMETEE, more ornamental (fig. 182) 



1 10 

 200 



This instrument has been carefully prepared under the suggestions of Dr. Mann, Vice-Presi- 

 dent of the Meteorological Society, to meet the special need of a trustworthy indicator of the 

 weather for farmers and planters. It is scrupulously correct, and has the further advantage of 

 being made portable or otherwise by the most inexperienced without possibility of injury. 



THERMOMETERS. 



The extended application of the use of thermometers to the various branches of 

 the arts and manufactures, as well as the precision and delicacy required in their 

 construction, renders a complete description here of all the varieties impossible. In 

 all branches of chemistry thermometers have long been indispensable, and but few 

 processes of manufacture are now conducted without their use. For most of these 

 purposes the following list will be found to contain the most suitable arrangement, 

 and fresh lists are published by L. CASELLA from time to time of every new kind 

 'brought into use. Besides the actual make of many of these thermometers, the mode 

 of dividing is of the greatest importance ; this is done on all CASELLA'S thermometers 

 of precision by means of a very beautiful arrangement of dividing engine, devised by 

 the great Ramsden, and now applied with the utmost facility to this purpose, certain 



