402 THIRD REPORT — 1833. 



daily mean temperature at this place from the annual mean is 

 pretty exactly proportional to the sines of the sun's declination 

 25 days before the day of observation. The mean temperature 

 of the year is 4S°-2; of July 62°, of January 34°-5. Average 

 quantity of rain 24 inches. Prevalent winds W. and S.W. : 

 about the vernal equinox N.E. winds are frequent. 



The Yorkshire Museum lies nearly west of the Minster, en- 

 tirely beyond the city, which here encircles the Minster by a 

 narrow belt of houses. Its roof is the highest in the immediate 

 vicinity : it stands free from other buildings, and is surrounded 

 on every side by the grounds of the institution. 



In these grounds, south-west of the Museum, the third sta- 

 tion is taken, in the midst of a large grass-plat. The second 

 and third stations are nearly equidistant from the Minster : 

 the intervening distances are. Feet. 



Between the Minster and the Museum gauges . 1100 ' 

 the Museum and garden gauges ... 136 

 Elevation of the gauges above the river, which is nearly 

 level with high water in the Humber : Pggt_ in_ 



Minster top gauge, raised on 9 ft. pole . . . 241 10| 



Museum top gauge 72 8 



Gauge in grovmds 29 



From these data it will appear that it would be difficult to 

 select three points more remarkably embracing the desired 

 conditions of gradation of altitude, openness of sky, and con- 

 tiguity of position. 



The gauges employed are of the simplest construction. A 

 cubical box of strong tin, exactly 10 inches by the side, open 

 above, receives, at an inch below its edge, a funnel sloping to 

 a small hole in the centre. On one of the lateral edges of the 

 box, close to the top of the cavity, is soldered a short pipe, 

 in which a cork is fitted. The whole is well painted. This is 

 the gauge. The water which enters it is poured through the 

 short tube into a cylindrical glass vessel graduated to cubic 

 inches and fifths of cubic inches. Hence one inch depth of 

 rain in the gauge will be measured by 100 inches of the gra- 

 duated vessel, and rA^th of an inch of rain may be very easily 

 read off. All the eauees were made on the same mould, and 

 the same glass jar has been used in every observation. 



The gauge in the ground has its edge nearly level with the 

 grass ; that on the Museum projects 1 1 inches above the stone- 

 work ; and the Minster gauge is supported on a pole nine feet 

 above the level of the battlements of the great tower, whose 

 top is 70 feet square. 



