COMPLETION OF THE NEW ROCK THERMOMETERS, 645 
~ So with 1879-0, now sur-abundantly proved to be the real date of that 
typical solar phenomenon, the last minimum of Sun-spots—which serves so 
usefully on this inquiry as a finger-post, or mile-stone of Solar physical energy, 
—TI applied on to that, as an absolute date, our thermometrical differences as 
before ; and behold, the result was almost perfect! For the very acme of the 
cold season came out just as it was experienced by every one in the end of 
1878 and beginning of 1879. And the following warm season is now upon us, 
increasing from day to day, exactly as the whole series of rock-thermometer 
observations long ago taught us, it ought to do at this time. 
Hence we may most certainly accept,—that if that admirable book of 
scientific predictions, the Government’s Nautical Almanac (which publishes 
four years beforehand several thousand minute particulars of the coming 
places of Sun, Moon and Stars), had only been enabled, by high learning and 
physical knowledge, to add thereto in 1876, the true date of the then impend- 
ing minimum of Solar-spots,—the cold season of 1878 and 9,—which the country 
had already been preliminarily and approximately warned about by me in 1872, 
—would have been most exactly spotted in 1877, or a full year and a half 
before it began. In which case Agricultural Science would doubtless have 
bent itself to a new task; and, elaborating some variation of farming for 
1879, suitable to a cold and wet year, might have saved no small portion of 
the hundred and fifty millions of pounds sterling which are said to have been 
lost in that year throughout Great Britain; and largely because the character 
of the season was generally unexpected, and therefore totally unprepared for. 
This then is the last of several insights into Nature, which the first set of 
rock-thermometers, by their forty years of observation, have just brought us in 
view,—not put us altogether into possession, of. For there remain many 
smaller variations of the cyclical quantities to be explained. And in order to 
give a clearer idea of both what has already been accomplished, and what 
remains to be done, I have, with obliging assistance from Mr Bucuan, who 
is Scottish Meteorology personified, and with help from the two assistant 
Astronomers on the Calton Hill, prepared a collection of various observations 
from 1821 to 1880, in Appendix 5; inclusive of course of our own rock ther- 
mometer results in a condensed shape ; and also such Sun-spot dates as I have | 
been able to gather ; those of the immortal discoverer of their periodicity, M. 
ScHWABE, being always preferred wherever they exist, viz., 1826 to 1868. 
A large Plate, No. XV., further represents these quantities graphically; and 
the whole, should it be approved and advocated by this Royal Society, may 
perhaps strengthen the hands of Government in doing for Sun-spots and Solar 
and Scotland, accompanied by the most violent magnetic storm that had been felt for many years 
(see “ Nature,” p. 361, No. 564, vol. 12; Aug. 19, 1880) ; while the Mean Temperature of that month 
turned out higher than for any August (that of 1857 excepted) chronicled by the Meteorological Society 
of Scotland, September too followed, with the same temperature characteristic—P, S., Oct. 1880. 
VOL. XXIX. PART II, ore 
