ON THE SEASONAL VARIATIONS OF TEMPERATURE. 455 



by season, actual meteorological conditions, tidal influence, &c. Tlie 

 grant of 201. "vvhicli was given to the Committee on its reappointment 

 was quite inadequate to pay the working expenses of the scheme and 

 admit of employing a competent person to tabulate and compute means 

 of the great mass of available material. 



It was accordingly resolved to confine the scope of this report to an 

 account of the observations made on the direct initiative of the Committee, 

 and to the statement of such brief summaries as might be supplied in 

 tabular form by previous observers. The main object held in view by 

 members of this Committee from its first appointment, viz. to produce an 

 authoritative and exhaustive memoir on the seasonal variations of tem- 

 perature in the lakes, rivers, and estuaries of the British Islands had to 

 be abandoned. At the close of its four years of existence the Committee 

 can only claim to add some additional data to the store awaiting future 

 discussion. This addition is of considerable scientific value, and casts 

 light on several problems in the regime of lakes and rivers. The obser- 

 vations have, however, led directly to another and perhaps even more 

 beneficial result. Great interest was taken by the Conference of Dele- 

 gates from local societies in the establishment of observations in their 

 own neighbourhood. The consciousness that they were engaged in col- 

 lecting data for a special and definite purpose has stimulated many of 

 the observers to a more earnest study of science, and done something to 

 forward that spirit of fellowship amongst all scientific workers which for 

 the last few years the Association has been so successfully advancing by 

 means of the annual conferences. The results of this stimulus may, it is 

 hoped, continue even when the observations which produced it have 

 ceased. 



The three previous reports of the Committee may be referred to for 

 particulars as to the method of working, the instruments employed, and 

 the period over which the observations extended ; a comparatively small 

 number were continued into the year 1891. The first report' was 

 mainly preliminary. The observations it records were upon rivers in 

 Scotland, and although several of the observers have continued their 

 work, most contented themselves with the record of a few months 

 only. The second report ^ notes a large accession of observers on the 

 rivers of England and of Ireland, and as an appendix the directions to 

 observers are reprinted, showing the conditions in which it was desirable 

 that all the observations should be made. In 1889 the reappointment of 

 the Committee was not accompanied by a grant of money, and the 

 observations in that year consequently sufiered to a certain extent. The 

 third report ' gives an epitome of the material collected by the Committee, 

 which forms the basis of the present discussion. The three previous 

 reports, it will be noticed, deal exclusively with the organisation and 

 extent of the observations, none of the data being recorded or discussed 

 in them. 



Some of the sets of observations have been published in detail. Of 

 these the most important is that accumulated by Dr. Sorby during the 

 years 1884-1888 on the estuaries of the south-east of England, which 

 appeared in the ' Scottish Geographical Magazine ' for 1889 (vol. v. 

 P- 589). An abstract of the results is included in the present report. 

 Observations on the River Thurso, by jMr. John Gunn and others, were 



* £.A. Eeportt, 1888, p. 326. = Ihid. 1889, p. 44. » Ihid. 1890, p. 92. 



