51 
ten feet or so over the houses in Church Street, from his 
workshop, distant, say 80 or 100 yards. He ran at once out 
on the hank, from whence he saw the water whirled up, as the 
commotion passed eastward out to sea.” At Ashhurne there 
was a gusty wind at the time, but nothing very noticeable.” 
Now the cut of this harogram, also one of Eichard Freres 
(the time is not correct), shows a rapid descent of 0 05 in less 
than an hour, followed by a sharp practically vertical fall of 
0*04 inch, and immediate vertical rise of nearly 0 03 inch. 
Then comes a curve closely resembling that at Owenshorough. 
We notice that this jerk down is hut double the York jerk 
although at the latter the disturbance was twentyfold more 
distant. This may partly, but by no means entirely, be 
ascribed to the latter being more violent. 
It would seem as if, in the immediate neighbourhood, there 
was a slight suction, changing, however, rapidly into an increase 
of pressure, which alone makes itself felt at greater distances. 
Or possibly, we have to deal with two different phenomena. 
The American tracings might throw some light on the question, 
if we can find how far off their records were made. But it can 
only he settled decisively if a whirlwind kindly develops itself 
in close proximity to one barograph, with a second at no great 
distance. 
We may perhaps refer here to one or two points of photo¬ 
graphic interest in the York micro-photograph. The ruled lines 
and figures in the original were red, except that the “ 8th ” 
upon the big 5, giving the date at noon, vas in black ink. 
The aneroidogram itself is in a violet aniline ink. At first 
Mr. Waller failed to get any signs of it, with ordinary plates 
and a magnesium flash, whilst even ortho-chromatic plates gave 
hut the ghost of a tracing. It then struck him that, possibly, 
the best results would be obtained with the more diffused and 
less intense light of an ordinary lamp, and he thus obtained the 
satisfactory negative from which our plate is taken. 
The second line, at the top, is the tracing of the previous 
week. The thickening, after 4 o’clock on the 8th, is a very 
usual concomitant of gusty or stormy weather. Indeed, the 
barograph makes thus its own record. 
