298 C. Ray Woods. — On some [Aug. 29; 



ON SOME PHOTOGRAPHS OF LIGHTNING FLASHES.- 



By C. Ray Woods. 



[Read 29th August, 1888.] 



The photographing of lightning flashes, it may be stated at the 

 outset, is no new thing. Many successful photos of flashes have 

 been obtained since the introduction of the Rapid Dry Plate Process 

 now so universally used, and some of these, having come under the 

 notice of the Royal Meteorological Society, the Society deemed the 

 matter of so much importance that a Thunderstorm Committee was 

 formed last year for the purpose of collecting and reporting on such 

 photographs. Circulars were sent out inviting specimens, with a 

 request to all amateur and professional photographers to assist the 

 Committee. The process is simple. A camera focussed for long 

 distance objects is pointed in the direction whence the flashes pro- 

 ceed, the carrier slide is withdrawn and the lens uncovered for a time- 

 It is advisable to remain on the watch and cover the lens after the 

 appearance of a flash in the field of view, and then to expose a fresh 

 plate. A series of flashes on one plate, though it might make a more 

 effective picture, would not lend itself so readily to scientific investigatioi]. 

 On the evening of July 30th last, I took advantage of the thunder- 

 storm that then occurred to expose a series of plates. The most 

 open view from my residence is in the direction of the Cape Flats, 

 and in that direction bright flashes, or sparks, to use a better term, 

 were frequently appearing. Care was taken to get only one flash on 

 each plate, with t^e result that the larger proportion were failures, . 

 but on several plates I obtained images which I pass round. Though 

 inferior and disappointing compared with the others to which I draw 

 your attention, such as this photo obtained by Mr. Hawksworth in 

 Natal, and particularly this fine photo obtained in Cape Town by 

 Mr. Allis about a twelvemonth ago, they are of some interest, I 

 venture to hope, in elucidating and amending the report just issued by 

 the Thunderstorm Committee already referred to. I wish particu- 

 larly to draw attention to the fact that the sky was almost covered 

 with clouds of varying thickness ; this not only rendered some of the ^ 



