Each vertical interspace represcnta one degree: Fahrenheit, and the fractional parts of a; de^-ee are indicated as exactly as possible in the ploiring' of die curves. Each fifth 

 uegress is represented Tay a Slighdy heaviec U'ne> The transverse interspaces inclosed by die heavier lines represent] periods of ten days each, as iadicated ty thfi dares Qn'iiie 

 left-hand side of the plate. The lighter* 'transverse lines, intermediate between' the heavier' bnes. are intended to represent the mean of each ten days, land the curves of tempeiv 

 ature ^re^plotted with'reference to these lines. 'The left-hand vertical division is devoted to' the, 'air temperatures for iSSt^ i8ii2 >and iSSj, the middle 'divisioti.io -the'surfaoa 

 Wateulemperaoires fon the same years, thus^ermittiog of a compariaoa of the two; and the rightJiand division to tlie virater temperatures for 18S4 and 18S5. 



