EIGHT YEARS OF THE NEW EARTH THERMOMETERS. 293 



how the extra length of that line from midsummer to autumn quarter in the one year 

 1881, is something perfectly phenomenal ; and at the same time is a fact as significant, 

 as it is irrefragable for the physics of both Earth and Sun. 



With the lowest thermometer (as is proper with heat from outside the earth) the 

 effect occurs later; viz. at the end of 1881 and beginning of 1882. 



But with the next less lowest, the chief effect is between autumn and winter of 

 1881. 



"With the next still less low one, the effect is earlier, or between midsummer and 

 autumn or a very little beyond. 



And with the shallowest of all the earth-thermometers, the effect, besides being- 

 tremendous in quantity — begins at midsummer sharp, and ends entirely by autumn 

 leading one to infer that for air above the earth, the effect may have begun a few days 

 even before June 30. Wherefore let us ask, did anything notably visible take place 

 either in the Earth's atmosphere or the Sun's photosphere at or about June 25, 1881, 

 capable of affecting the earth's temperature to some very sensible degree \ 



Now there was something of that kind, whether noticed yet in this category or not 

 by other observers, I am not aware ; but it was recorded by myself in such an entirely 

 independent manner at the time, without the slightest reference to Edinburgh Earth- 

 Thermometers, that I was surprised indeed on completing their diagrams last night to 

 have the 1881 date so pointedly and reiteratingly presented to me again, and shown to 

 be something that had made its mark in nature. 



I was in the Island of Madeira at the time, spectroscoping the Sun, mapping the 

 Sun-spots each day, and meteorologising. 



On June 21, 22, and 23, the Sun-spots were feeble exceedingly, and apparently bent 

 on closing up. But on the 24th it is chronicled in my observing book that " two new 

 outbreaks of Solar activity, appear in the Sun's North Tropic, one East and one West." 



On the 25th, the note is " The importance of the new centre of Solar activity on the 

 North-East Limb is maintained. There are now three spots there and large faculse." 



On the 26th there were no spot observations. But on the 27th, the note runs 

 thus, — 



" Sun-spots at 7 h a.m. Solar definition horrible ! caused probably by extra Solar 

 heat. But the magnificent display of renewed Solar energy in the new Spots, especially 

 those in the South Tropic, cannot be hid ; and it may have a bearing on the wonderful 

 Cloud, which so greatly astonished and alarmed the inhabitants here all yesterday after- 

 noon and evening." 



Now what was that cloud of June 26, with so unusual an aspect, that the inhabitants 

 of Madeira were in consternation about it % 



In the little book entitled Madeira Meteorologic (the expense of printing which was 

 so kindly volunteered for and borne,— as I am now, alas ! free to declare, — by that kindly 

 and generous minded gentleman and F. R.S.Ed., the late Robert Mackay Smith), the 

 whole of its " Part iv." or pp. 33 to 50, with two woodcuts and the very artistically en- 



VOL. XXXV. PART 3. 3 C 



