236 MEMORIES OF MY LIFE 



was then etched by acid. The result was to produce 

 quarto copper plates, each containing the whole of 

 the instrumental data for each of the seven stations 

 for five consecutive days. The original tracings are 

 reduced to the ratio of 6 : i in horizontal and 2 : i in 

 vertical measure. This work was steadily pursued 

 for twelve years, which is long enough to include a 

 complete cycle of solar sun-spots. The illustration is 

 a facsimile of the upper two lines of one page, from 

 which the fourth and fifth days have been removed, 

 for want of space. 



It surprises me that meteorologists have not made 

 much more use than they have of these compre- 

 hensive volumes. But there is no foretelling what 

 aspect of meteorology will be taken up by the very 

 few earnest and capable men who work at it. Each 

 of them wants voluminous data arranged in the form 

 most convenient for his own particular inquiry. 



I take this opportunity of mentioning another 

 attempt of mine which was not brought into practice 

 but may hereafter be useful ; at all events, it is of 

 interest. The object was to gain some knowledge 

 of the upper currents of the air, such as are now 

 being obtained by small balloons or kites, which 

 carry self-recording instruments. It seemed to me 

 that the cloud made by a bursting shell fired high 

 in the air over the sea, at a little frequented part 

 of the coast, as that of West Ireland, when no vessel 

 was within the possibility of damage from falling 

 fragments, ought to give what was needed. The 

 first questions to be answered were as to the height 

 to which a shell of appropriate size could be sent, 

 the visibility of the result, and the cost of each 



