f 



ON THE SEASONAL VARIATIONS OF TEMPERATURE. 327 



List of Thermometers brolcen. 



Cause of Breakage Number 



In transit 6 



During observations 7 



By accident when not in use . . . . . . . 1 



Unaccounted for • . 2 



Total . . 16 



Accurate mercurial thermometers by Adie & Weclderburn, divided 

 ou the stem and fitted into copper cases, and costing 7s. 6cl. each, had 

 previously been used ; but the expense incurred by accidental breakage 

 was great, and as many of the observers read only to quarter of a degree, 

 it seemed unnecessary to employ such delicate instruments. A number 

 of small mercurial thermometers with cylindrical bulbs, and provided 

 with paper scales divided into Fahrenheit degrees from 10° to 120°, were 

 accordingly ordered from Germany, and supplied at the rate of 15s. per 

 dozen. 



Japanned tin cases were made in Edinburgh for 1.3s. per dozen, in- 

 cluding an outer tin case for travelling, the total cost being thus 2s. 4rZ. 

 each. All the thermometers were compared with the Kew standard in 

 the Chemical Laboratory of the University of Edinburgh, and the 

 corrections noted ; these rarely exceeded 02°, and in many cases were 

 negligeable. The instruments appear quite suited for the work, and can 

 be replaced when broken at a trifling cost. More careful packing will 

 practically obviate breaking in transit, and as the observers gain ex- 

 perience accidents occur less frequently. The observations on the Tay 

 river system are of particular interest, as there were a number of stations 

 on the main river, its tributaries, and feeding lakes. The curves for the 

 various stations from December or January down to April, and in some 

 cases to July, show distinct diSerences, due to the nature of the country 

 drained by the rivers and to the altitude. 



The care and regularity with which the observers in general carried 

 out their work convinces us that it is quite practicable to carry on the 

 observations on a large scale, and that it is desirable to extend it to 

 England as well as to enlarge its scope in Scotland. Tour Committee 

 accordingly recommend that they be reappointed, with a grant of 50Z. to 



be expended as follows : — 



£ 



Clerical assistance 20 



Observation books and circulars 15 



Thermometers .... 10 



Postages of instruments, books, &c 5 



Total . . 50 



The Secretary desires to say that while he has taken the general 

 oversight of the work, the actual arrangements have been mainly carried 

 out by Dr. H. R. Mill, assisted by Mr. John Gunn of the ' Challenger ' 

 office. The Secretary also begs to resign his position, and the Committee 

 recommend that Dr. Mill be appointed in his place. 



Several stations besides those included in the above list have been 

 lately established, but sufficient time has not yet elapsed for the observers 

 to have collected data sufficient to be reported upon. 



A discussion of the more important results of these observations will 

 be submitted to this meeting by Dr. Mill. 



