470 Mr. S.E. Hoskins on a Tabular Form of Analysis. [May 9, 



III. A Tabular Eorm of Analysis, to aid in tracing the Possible In- 

 fluence of Past and Present upon future states of Weather/^ By 

 S. Elliott Hoskins, F.R.S., &c. Received March 28, 1867. 



The data upon which the present communication is founded are derived 

 from the ' Greenwich Reports,' from Mr. Glaisher's papers in the Philo- 

 sophical Transactions, and from my own observations at Guernsey. The 

 latter were commenced in the autumn of 1842, in accordance with the re- 

 commendations of the Committee of Physics of the Royal Society, and 

 were taken at the request of Professor Daniell, by whom the instruments 

 employed were selected. These instruments, made by Newman, were after 

 a time replaced by others, at the suggestion of Mr. Glaisher, by whom 

 they were compared with the standards at the Royal Observatory. 



For my own guidance in the first instance, I sought to arrange the re- 

 sults thus obtained in such a manner as to discover, if possible, whether 

 any month or class of months stood to each other in the relation of cause 

 and effect ; in other words, whether the atmospheric conditions of autumn 

 exercised any distinguishable influence upon the fruitful or unfruitful 

 character of ensuing seasons. 



In order to attain this object, the principle seemed to be that of con- 

 densing within narrow limits, by means of intelligible symbols, as many 

 elements of weather, in the popular acceptation of the word, as might be 

 required. But the ordinary curvilinear form of diagram could not be so 

 modified as to answer this purpose, and I therefore availed myself of a plan 

 suggested by Mr. Galton : — that of converting the records of observations 

 into appropriate signs, and placing them compactly in a series of squares. 



Upon this principle the annexed diagrams* are constructed, comprising 

 those elements of weather which more directly affect vegetation ; viz. heat, 

 cold, dryness, moisture, and their combinations. The same kind of pre- 

 paratory steps were taken for the compilation of the Greenwich as for the 

 Guernsey diagram, so as to render the results comparable — less, perhaps, 

 for the sake of mere comparison, than for the purpose of testing the value 

 of the latter by means of an accredited standard. 



The first process consisted in copying out the degrees of monthly mean 

 temperature, the number of rainy days, and the days of wind, from four 

 directions, intermediate to the cardinal points. These several copies being 

 verified, the monthly average of each of the above elements for twenty 

 years, from 1843 to 1862, was taken. 



The next step was to obtain the difference between the adopted average 

 and the mean of each month in every year. By prefixing the plus and 

 minus signs to the resulting figures, the excess and defect of each element 

 is shown. 



The third process was to separate the above-mentioned series of years 



* [The diagrams are not published, but are preserved for reference in the Archives 

 of the Society.] 



