TKANSACTIOKS OF SECTION A. 



509- 



meters became practically the same ; and hygrometry was relieved of the old draw- 

 back on its non-refifistrations of maximum and minimum quantities of moisture im 

 every twenty-four hours. 



14. 



Eighteenth Beport of the Gommittee on Underground Temperature. 

 See Reports, p. 35. 



15. Second Report of the Committee appointed to arrange an investigation of 

 the Seasonal Variations of Temperature in Lakes, Itivers, and Estuaries- 

 in various parts of the United Kingdom. — See Reports, p. 44. 



16. On the Temperature of the Tidal Estuaries of the South-east of England. 

 By H. C. SoRBY, LL.D., F.B.S.^ 



The observations made by the author on his yacht 'Glimpse' during the 

 summer months of 1884-88 have been discussed for the Committee on Seasonal 

 Variations of Temperature in Estuaries, &c. The estuaries examined were all 

 those lying between tlie Strait of Dover nnd Lowestoft; their depth averaged from 

 1^ to 4 fathoms. Observations were at the same time made on the stretch of more 

 open water into which these estuaries open ; this had an avei-age depth of 6 

 fathoms. Temperature was observed both at surface and bottom, but the diflerence^ 

 between the two was usually slight. The mean results for the five years 1884-88 

 are as follows : — 



The excess or defect of temperature at low water varied in each year, but the 

 low-tide temperature was higher, except in September and sometimes in May, 

 showing that the landward water responded more quickly to the change of the 

 seasons and had a greater range of temperature than that of the more open sea. 

 The diurnal range of temperature in tlie water came to a maximum in July and 

 then decreased. During the months under consideration the increase of tempera- 

 ture by the day's heating was found to be 1-07° at high water and 1-71° at low 

 water ; the fall of temperature produced by the night's cooling 0-70° at high water 

 and 1-50° at low water. This shows that the depth of (he estuary and the rela- 

 tively large proportion of river water are the chief factors in determining the efl'ect 

 of radiation on water temperature. 



17. Apparatus for reading Indications of distant Meteorological Instruments. 



By T. J. MuEDAY. 



18. On the Periodical lieturn of Storms. By T. J. MuRDAY. 



In this paper the author dealt with the subject of recurring periods, and by 

 means of charts and tables of storm cycles demonstrated the fact that certain (if 



' Published i)i cxtento in the Scotch Oeographical Mcu/azine. 



