Aneroid Barometer. 
123 
The following example, by which the height of a meteorolo- 
gical station and other points were determined, will show the 
manner of using the Aneroid : — 
Difference 
Corre- 
amber of 
Station. 
Places. 
Reading 
of 
Aneroid. 
Correction 
lor vfl,riti- 
lion of 
Pressure. 
True 
Pressure. 
of Pressure 
between 
Datum 
and 
sponding 
height 
above 
Iz; 
Station. 
Datum. 
1 
Datum, lowest step of Parade, j 
Truro, 15 feet above meaul 
29-83 
29 
83 
2 
Mw.liull Rill Po+o 
29 -62 
A- -01 
29 
63 
• 20 
190 
3 
Road at Buckshead Cottage 
29-50 
+ -02 
29 
52 
•31 
294 
4 
Koad over Buckshead Tunnel 
29-54 
+ -03 
29 
57 
•26 
247 
5 
29-45 
+ -03 
29 
48 
-35 
332 
6 
29-47 
+ -04 
29 
51 
•32 
304 
4 
29-51 
+ -05 
29 
56 
•27 
25G 
3 
Again returning 
29-47 
+ •05 
29 
52 
•31 
294 
7 
Turnpike - road north of\ 
29-53 
+ •06 
29 
59 
-24 
228 
1 
Datum on returning . . 
29-76 
+ •07 
29 
83 
To each of which 15 feet must be added to give the heights 
above mean sea-level. No. 4, by accurate levelling for railway 
purposes, is 251 feet above the datum. Two other independent 
observations of the Aneroid gave for No. 7 respectively 230 and 
235 feet above this datum, showing how nearly the barometer 
approximates to the truth. 
The following table of elevations has been computed, answer- 
ing to the corresponding depressions of the barometer :* — 
Height of 
the 
Barometer. 
Feet. 
Height of 
the 
Barometer. 
Feet. 
Height of 
the 
Barometer. 
Feet. 
Inches. 
Inches. 
Inches. 
30-0 
28 
6 
1,315 
27 
2 
2,692 
29-9 
92 
> 28 
5 
1,411 
27 
1 
2,793 
29-8 
184 
: 28 
-4 
1,508 
27 
0 
2,895 
29-7 
276 
28 
3 
1,605 
26 
9 
2,997 
29-6 
368 
28 
2 
1,702 
26 
8 
3,099 
29-5 
462 
28 
-1 
1,799 
26 
7 
3,201 
29^4 
556 
28 
0 
1,897 
26 
6 
3,304 
29-3 
650 
27 
9 
1,996 
26 
5 
3,406 
29-2 
744 
27 
8 
2,095 
26 
4 
3,511 
29-1 
838 
27 
7 
2,194 
26 
3 
3,615 
290 
933 
■ 27 
6 
2,293 
26 
2 
3,719 
28-9 
1,028 
27 
5 
2,392 
26 
1 
3,824 
28-8 
1,123 
27 
4 
2,491 
26 
0 
3,926 
28-7 
1,219 
27 
3 
2,592 
25- 
0 
5,000 
* Manual of the Barometer, by J. H. Belville. 
