UNCLE IN ENGLAND. 317 



and that its direction is just at right angles to 

 the direction of their flight. 



My uncle was greatly interested by the Co- 

 lonel's account of this remarkable swarm, and 

 proposed that we should endeavour to make 

 some estimate of the number of locusts of which 

 it consisted. We all took out our pencils and 

 went to work. In the first place, the breadth of 

 the column was 40 miles, or 70,400 yards ; and 

 as their ranks were a foot apart, we have 211,200 

 for the number of locusts at each foot of eleva- 

 tion. Colonel T. was then examined as to the 

 entire height ; he thinks it must have been much 

 above 300 yards, for on looking upwards with 

 his pocket telescope, he could see them like little 

 specks glittering in the sun. We contented our- 

 selves with the 300, and taking them also at a 

 foot apart, there were of course 900 locusts in 

 height, by which we multiplied the former num- 

 ber, and the product was 190,080,000. Now, 

 mamma, for the length of the column : he says 

 there was a gentle breeze from the southward, 

 with which, and their own velocity, he thinks 

 that they were travelling at the rate of about 

 seven miles in an hour, and that they succeeded 

 each other at an average distance of three feet. 

 In each mile, then, there were 1760, and in 

 seven miles, 12 5 320, which, multiplied by 72, 

 the number of hours in the three days which the 

 flight continued, gives 887,040 for the number in 



2E 



