121 
month in which the explosion occurred ; and it is also 
remarkable that these are found in the months of January 
and May, which are among the months when the fewest 
explosions took place. It is tolerably clear that there is 
a greater tendency to explosions in coal pits when the 
barometer is low, and that the tendency is increased when 
the barometer is falling. 
It is, therefore, very desirable that the state of the 
barometer should be carefully watched, and additional care 
exercised when it indicates a diminishing atmospheric 
pressure, so as to guard against the danger arising from 
an increased flow of inflammable air into the pit. 
Table I. of 79 Colliery Explosions in the District inspected by 
C. Morton, Esq., showing the relative state of the Barometer 
on the days of explosion, and at certain other times. 
A Height on day of Explosion. 
B Height on day before. 
C Height on day but one before. 
D Mean Height of the month. 
E Mean Height of the whole period. 
Amount of 
Difference of 
Barometer 
Reading. 
.000 
A 
less 
than 
B 
6 
A 
greater 
than 
B 
10 
A 
less 
than 
C 
2 
A 
greater 
than 
C 
4 
A 
less 
than 
D 
5 
A 
greater 
than 
D 
3 
A 
less 
than 
E 
4 
A 
greater 
than 
£ 
3 
.100 
22 
8 
21 
8 
12 
9 
13 
6 
.200 
17 
2 
11 
3 
8 
6 
12 
3 
.300 
5 
10 
1 
7 
11 
13 
.400 
6 
8 
2 
3 
4 
7 
.500 
1 
4 
4 
2 
5 
.600 
1 
4 
.700 
1 
1 
1 
.800 
2 
2 
.900 
1 
1 
3 
1.000 
1 
1.100 
1 
1.200 
1.300 
1 
1 
1 
1.400 
1.500 
1 
1.600 
1 
59 
20 
60 
19 
44 
35 
66 
13 
I 
