MB. A. W. L’RESTON ON THE GREAT FROST OF 1891 -5. 
97 
1890 — 91, that both the mean maximum and the mean minimum 
and the absolute maximum temperatures were slightly higher, but 
that the absolute minimum was 3 degrees lower than in the last 
named year. The days of minimum temperature below 20 degrees, 
of continuous frost and of maximum temperature above 40 degrees 
were nearly identical in each winter, but the days with daily mean 
32 degrees or below, and with maximum temperature 32 degrees or 
below, were in 1890 -91 very greatly in excess of those in 1894 — 95. 
On the whole, therefore, it may be said that the frost of 1894 — 95 
fell short both in duration and intensity of that of 1890 — 91, but 
that it gave three colder nights. With regard to the other winters 
in the table, it will be seen that 1894 — 95 outstripped all but one 
in duration, but the mean temperature was lower in each of the 
other winters except 1879. The absolute minimum was, however, 
only equalled in 1838. 
(ft) January 22nd to February 20th (30 days). This period is 
inserted for the sake of comparison with the shorter winters in the 
table, such as I860 — 01 and 1881, it having been the coldest period 
of our recent winter. It will be seen that the mean of this section 
of the winter was lower than 1800 — 01, but higher than 1881. 
(c) December 30th to February 20th (59 days). This is inserted, 
because the number of days coincide with the winter of 1890 — 91. 
The table, however, shows here, more than under (a) that the recent 
winter was decidedly the milder of the two. 
(d) December 30th to March 5th (06 days). — Owing to the 
renewal of the snowfall and severe frost at the end of February and 
early days of March, it is considered by some that the recent winter 
should be taken to have covered the above period. But the mild 
break in the third week of February raised the mean to 31.9 degrees, 
or so much higher than any other in the table that, had it been 
inserted as alone representing the recent winter, many other seasons 
should also have been admitted; in fact, the winter of 1813 — 14 
should be extended to March 20th (85 days), as the frost in that 
year actually lasted from December 20th to March 20th, with a 
break of ten days in the middle of February. 
It should be mentioned that Mr. Harding’s table was compiled 
from observations made in the neighbourhood of London. The 
temperatures of the frost of 1788 — 89 were not taken from self- 
registering thermometers, but from instruments read at 8 a.m. and 
2 p.m. daily. All the other observations in the table are from self- 
registering thermometers. 
VOL. VI. h 
