Each^.er.tical interspace represents one degree Fahrenheit, and the fractional parts of a degree are indicated. as exactly as possible in the.plotting of the curves. Each.fifth 

 degree is representeaTjy-a slightly 'heavier line. The transverse interspaces inclosed by the heavier lines represent periods of ten days' each, as indicated by the dates on the 

 left-iana'si'de'cE'thejplate.. Theilighter- transverse lines, intermediate between the heavier ones, are intended'to represent'tlie mean of each ten days, and the-curves of temper- 

 atureate plQtte#'withjiefer.ence to these lines. The left-hand vertical division is devoted to the sun temperatures for tSSi 18S.2 and 1883, the middle division to the surface 

 watertemperaturesvfcr^e^ame years, thus permitting of .a comparisoji of the. two;' and-the rightJiand division to the water temperaturesfor-i 884 and 1SS5. 



