OF METEOROLOGICAL INSTRUMENTS. 



31 



FIG. 74. 



FIG. 84. 



meter is kept in a light metallic case, lined with india rubber. The portable 

 leather case (fig. 85*) p. 32, contains the whole when packed for travelling. 

 Price, with one thermometer, divided to 01, as arranged and made by L. 

 CASELLA for the Government (fig. 85) p. 32 . . 4 15 



86. Pocket Hypsometer. The success attending the above has induced L. CASELLA 



to construct a still smaller instrument on the same principle, which is much 

 used by Alpine travellers. It may be carried with ease in the pocket, and by 

 those a little experienced in its use, is often preferred for its simplicity and 

 certainty to the mountain barometer. With one thermometer divided to 2, 

 as supplied to the Eoyal Geographical Society . . 2 10 



Wherever the measurement of mountain heights is required to be taken by other means than 

 the theodolite, or standard barometer, or where there may be danger of damage or breakage 

 of either, without an easy means of comparing or replacing them, this cheap and simple 

 means of measuring heights will be found as efficient as it is handy, and at all times a reliable 

 test of the aneroid or any other instrument, which from time to time require to be compared 

 and adjusted. 



87. Casella's Tables^ with instructions for using the hypsometer, second edition 



1 



" For the elevation 

 metrical results are as goc 



point thermometer supersedes the barometer in point of practical utility, , _ . 



transport of a glass tube full of mercury, nearly three feet long, and cased in metal, is a great drawback to the 

 unrestrained motion of the traveller." Dr. J. D. HOOKER'S " Himalayan Journals " Vol. II. 



