( 637 ) 
XXII.—Notice of the Completion of the New Rock Thermometers at the Royal 
Observatory, Edinburgh, and what they are for. By Professor P1azzi 
SmytuH, Astronomer Royal for Scotland. 
(Read 5th July 1880.) 
INTRODUCTORY ACCOUNT. 
PAGE 
The making and placing of the new thermometers, : : : ; : ; : 637 
Practically described by Mr THomas WEDDERBURN, : é ; : ‘ : : 638 
The problem with the old thermometers, . ¢ é : : : : : : 639 
Their next use in level fluctuations, : : ‘ F 5 639 
Their employment in Earth-heat history, ne Sir aie Tnoueont : . 640 
Their subsequent discovery, in 1870, of the eleven year cycle of supra-annual waves of fen mae cold, . 641 
The published predictions in 1872, for 1878°8 and 1880, . c : . - : 642 
The spoiled predictions in 1877, under the influence of erroneous Sun- ee dates, : 2 643 
The rectified predictions in 1879, when the true date of that Sun-spot minimum was Seeaeinea, 5 644 
How to obtain sufficiently correct dates of future Sun-spots minima,—to enable predictions of weather 
to be useful to national agriculture, . : : : : : : é : 645 
AppEnpIx I. The Contract for the new Thermometers, : ° é ¢ 5 : 646 
II. Account of works by Mr Ricnarp ADiIn, : : ; : : 647 
III. Further account by Mr T. WepprrBury, of ADIE & Som é < 5 : 647 
IV. The Cyclical seasons of 1879 and 1880, as predicted in 1872, . c E 649 
V. Scottish Meteorological Data from 1821-80, arranged in Quadruple Annual means for 
Cyclical inquiries, : é : : é ; : : 650-656 
PuatE, No. XV, representing the above numerical tables, graphically. 
On the 26th of last month the full year appointed by Government Contract 
for the testing of the new Rock-Thermometers having expired, and they having 
approved themselves at all points, been accepted, and set fairly afloat on a new 
course of observation,—I hasten to announce the event to the Royal Society, 
Edinburgh, who have long had a lively interest both in these instruments and 
in the problems they have been employed upon. 
Those new thermometers, viz., four more or less gigantic and deeply sunk 
in the rock, supplemented by two smaller ones for surface and air temperatures, 
are almost exact counterparts of the former magnificent set, which was so wil- 
fully and calamitously destroyed by a Portuguese madman early one September 
morning in 1876, after having been continuously recorded at the Royal Obser- 
vatory, Edinburgh, ever since 1837. 
Now those earlier thermometers were constructed at that date by Messrs 
Avie & Son of this city, at the expense of the British Association for the 
Advancement of Science, but according to the plans of Professor JAMEs Darp 
VOL. XXIX. PART II. 7 Q 
