Cotswold Hills, with observations on the Aneroid Baroineter. 257 



in the " vacuum- vase " of the instrument. This however is, I 

 believe, a mistake*. 



In its present form, then, I conclude that a correction for 

 temperature is needed for the exact measurement of heights. 

 There are also two palpable defects, one of which is that the hand 

 or index is frequently so far from the face of the dial, that its 

 parallax leads to error in reading off the scale, which may easily 

 amount to 20 feet in height. This however may be somewhat 

 corrected by bending the hand so as to make it nearly touch the 

 face of the dial. The other fault is that the inch is subdivided 

 into only forty parts, one of which corresponds to 22 feet in 

 height. It would be better to have it graduated to hundredths 

 — so that the actual reading off should tally at once with the 

 barometric tables now in use — or if the size of the dial will not 

 admit of this, to subdivide the inch into fifty instead of forty parts, 

 so that each division should be "02 of an inch. At present, in 

 order to use the tables, it is necessary in reading off to change 

 the vulgar fractions into decimals, which, in jotting down, fre- 

 quently leads to troublesome mistakes. 



It is full time however to come to the table which I promised 

 of the 



Approximate altitudes above the mean level of the Sea supplied 

 by Capt. Yolland, R.E. 



By Ordnance By Aneroid Difference 

 Survey. Barometer, by Aneroid, 

 feet. feet. feet. 



Tewkesbury Church, surface of ground ... 47 

 Gloucester Cathedral, surface of ground ... 56 



Barrow Hill, surface of ground 1 9B 



Corse Hill 292 



Christ Church tower, Cheltenham (top)... 343 



Robin's Wood Hill 652 634*2 -17-8 



Standish Hill 715 691-4 -23-6 



Stinchcombe Hill 725 740*27 +15-27 



Finger-post on top of Frocester Hill 780 



Oxenton Hill 733 



Firs at Symond's Hall 810 



UleyHill 823 8255 +25 



Painswick Hill 929 935-9 +6-9 



May Hill 966 



BirdlipHill 969 960-5 -8-5 



Leckhampton Hill 978 969*9 —8-1 



Base of Bredon Hill tower 979 



Cleeve Hill or Cleeve Cloud 1081 1066*8 -14*2 



Malvern 1396 



With the exception of Standish and Robin's Wood Hills, the 



* I have since ascertained it to be one. M. Vidi himself informed me in 

 November last, that although he at one time made some experiments on 

 the use of gas in the "vacuum" — (qy.) "vase," — he has now rejected it 

 altogether. 



Ann. ^IVfag.N. Hist. Ser. 2. Vol\. \7 



