8o 
THE WINDRUSH AT BIGGIN. 
The Biggin details indicate a marked general resemblance to 
the “ windrush ” from Bishopthorpe to Heslington on March 8th, 
1890.* This, also, was only an episode of a line squall and of the 
same March period as the other two. Barograms from York, 
Leeds, Huddersfield and Hodsock all show the characteristic 
jump, and a thunderstorm with a front of at least 50 miles was 
traced as it passed York in the same S.S.E. course as the other 
two. This squall took 2 \ hours to reach the Rev. \V. C. Ley at 
Lutterworth, 95 miles further on, again giving a velocity of about 
38 miles per hour. 
Thus we are brought back to the conclusion that the main 
factor at Biggin was a windrush, subsidiary to and moving across 
the face of the line squall. The actual cause of the phenomenon 
is certainly obscure. This much seems certain, that the squall 
line is one of collision between warm south-westerly and cold 
north-westerly air currents. It is probably associated with a 
secondary depression, the primary depression lying over or near 
Southern Scandinavia. It may be accidental, but it is at least 
noteworthy that the three, which have led to more or less complete 
investigation, occurred at or a little before the spring equinox. 
* Y. P. S. Report ; Q. J. R. Met. S., July, 1890; and (further important 
details and charts) N. H. Journal, November and December, 1890. 
