1872.] Weather Prophecies. 435 
the message would have allowed only two hours for pre- 
paration, and would have arrived while the eastern men 
were sound asleep. If a message could have been sent 
from Iceland the day previous to the arrival of the storm, 
many wrecks would have been prevented. So that we 
see the present system of meteorology necessitates not 
only diligent but earnest watching of the signals that 
should be afforded by a network of cables and overland 
wires, for it is by a series of connected observations, ex- 
tended over a large area, that the usefulness of this branch 
of meteorology is alone likely to be advanced. 
But, it may be asked, what definitive knowledge can be 
gained, say not of storms, but of average weather for some 
future period? Here we must again refer to Professor 
Piazzi Smyth’s report on the rock-thermometers at the 
Royal Observatory, Edinburgh, and to the Proceedings of 
our own Royal Society for the 2nd of March, 1870, in which 
predictions of the weather during the winters of 1871-72 
are attempted. The rock-thermometers have by their read- 
ings shown some well-marked supra-annual cycles, the 
relation of which to the sun-spot cycles will be known to 
our readers. And on this point it may be stated that the 
Radcliffe astronomer announces in his report for 1871, that 
the mean azimuthal direction of the wind at Oxford, rigo- 
rously computed from automatic records during the last 
eight years, varies year by year through a range of 58° on 
the whole, between maximum and minimum of visible sun- 
spots ; the tendency of the wind to a westward direction 
increasing with the number of spots; and with such west 
wind, it is to be presumed, the amount of rain also. ‘‘ The 
most striking and positive feature of the whole series of 
observations,” continues Professor Piazzi Smyth, “is the 
great heat-wave which occurs every eleven years and a 
fraction, and nearly coincidently with the beginning of the 
imerease of each sun-spot cycle of the same eleven-year 
duration. The last observed occurrences of such _heat- 
wave, which is very short-lived, and of a totally different 
shape from the sun-spot curve, were in 1834°8, 1846°4, 
1857°8, and 1868°8 ; whence, allowing for the greater uncer- 
tainty of the earlier observation, we may expect the next 
occurrence of the phenomenon in or about 1880'0. The 
next largest feature is the extreme cold close on either side 
of the great heat-wave: this phenomenon is not quite so 
certain as the heat-wave, partly on account of the excessive 
depth and duration of the particular cold wave which 
followed the hot season of 1834°8. That exceedingly cold 
