1867.] Mr. S.E. Hoskins on a Talmlar Form of Analysis. 471 



into two decennial periods or decades, and then to compute, not onlj the 

 number of mouths above and below the average, but also the degrees of 

 temperature. (See Tables I., II., III., V. and VI. in the Appendix.) ] 



Lastly, the numerals thence derived were converted into simple and 

 familiar signs, v>-hich were then delineated upon a sheet of sectional paper, 

 accurately engraved according to scale. A square space was allotted to each 

 of the months, and they were laid down as abscissas, with the years for 

 ordinates. (See Diagrams I. and II. (Archives).) 



The light squares in the diagrams denote warmth, the degrees being 

 expressed by a modification of the plus sign, in red ink; the dark, or 

 shaded squares indicate cold, and the degrees are marked in black ink 

 with the minus sign. Black dots indicate the number of rainy days above 

 the average, and red dots the number below it. The diagonal lines from 

 the centre of each square show the direction and days of predominant 

 wind, one-sixteenth of an inch being equivalent to five days beyond the 

 mean ; the red lines are associated with dryness, and the black with 

 moisture. It may be necessary to explain that, as regards rainfall, frequency, 

 rather than quantity, was selected as a criterion. That is to say, the number 

 of days on which rain fell rather than the number of inches collected by 

 the pluviometer ; for it not unfrequently happens that a few heavy showers 

 yield a greater amount of water than many days of gentle rain of long 

 continuance. 



The combined signs in the above arrangement are intended to represent 

 four different states of weather, viz. warm + dry ; warm + wet ; cold + dry ; 

 and cold + wet. 



If the sectional paper be large enough to admit of blank spaces being 

 left, the signs of the weather may be delineated therein as each month 

 elapses ; and thus the diagram becomes a sort of register, and an ever-ready 

 table of reference. 



For instance, by running the eye along the vertical columns of the 

 Guernsey diagram, to which I must confine myself for the present, the 

 existing state of the w^eather can easily be compared with that of corre- 

 sponding months, up to 1843 ; and by following each horizontal line of 

 squares the character of each year may as readily be ascertained. Thus 

 we shall find, on comparing the September of 1865 with that of preceding 

 years, that it was the hottest and the driest of the whole series. On look- 

 ing along the ordinate corresponding to 1846, it will be seen that during 

 eleven months of that year the temperature was uniformly above the 

 adopted average. 



On taking a general view of this diagram, after its completion, a very 

 cursory glance sufiiced to show me that a striking difference existed in the 

 distribution of light and shade. On closer inspection, it became manifest 

 that the number of light squares in the one decade exactly counter- 

 balanced the dark squares in the other ; so that the warm months of the 

 first period were in direct ratio to the cold months of the second. 



VOL. XV. 2 11 



