61 
probably not exact) passing over from S.E. to N.W. It 
was described to me as lighting up the whole street^ colour 
reddish green!' This shows that it was observed from 
Eochdale in the east to Cookstown in the west, a distance 
of nearly two hundred miles. 
“The Lowest Amounts of Atmospheric Pressure during 
the last Sixteen Years, as observed by Thomas Mackereth, 
F.RA.S., F.M.S.” 
The following are the lowest pressures of the atmosphere 
observed at Eccles during the last 16 years. Each reading 
of the barometer has been reduced to 82° Fahr. and the 
height at sea-level. The weekly means are for the whole 
week in which the lowest reading was registered. No 
minimum reading has been considered which, at sea-level, 
would be 2 8 '6 inches. 
Year. 
Month. 
Date. 
Time of 
Observation. 
Lowest reading 
reduced. 
Mean Height 
for 
the week. 
1865 
January 
14 
9 a.m. 
Inches. 
28-360 
Inches. 
29-277 
1867 
Si 
8 
Si 
28-558 
29-228 
1872 
Si 
24 
Si 
28-454 
29-253 
1873 
Si • • * 
19 
11.30 p.m. 
2S-327 
29-127 
1876 
March 
10 
9 a.m. 
28-568 
29-173 
1876 
December 
4 
Si 
28-379 
29-143 
The lowest reading for January 19 tli 5 1873, was the 
absolute minimum, as the barometer was read every half 
hour till the minimum had been reached and the mercury 
began to rise. There does not appear to be any order or 
rule which these low pressures follow. The only thing 
rem.arkable is that four of them in succession occured in the 
month of January, and with one exception they all took 
place in the morning. 
The directions of the wind during the low atmospheric 
pressures indicated in the above table were as follows : — 
