230 
Col. R. Meinertzhagen on the [Ibis, 
arrive in such numbers on our central east coast. The 
Bluethroat estimate is based on the assumption that birds 
fly direct from Egypt to Heligoland in one night, which is 
certainly not the case. His estimate of the flight of Godwit 
and Curlew, on which he bases his estimate of the flight of 
the American Golden Plover, is, I fear, but an example 
of the tremendous enthusiasm of this charming character 
for his subject. 
But Gatke is not alone in over-estimating the velocity 
of flight. Many other writers have erred through basing a 
theory on bad evidence or no evidence at all, one of the 
most remarkable of these being Crawfurd (‘ Round the 
Calendar in Portugal*), who convinced himself that Turtle- 
Doves flew at such an astonishing pace that by leaving Kent 
at dawn they would be in Portugal a few hours later ! 
As regards more accurate data, it was my fortune during 
the recent war to have the opportunity of using anti-aircraft 
arrangements for my purpose. It was excellent practice for 
the men, and the results can be taken as accurate for all 
practical purposes. In conjunction with observations of an 
accurate nature from other sources, I have compiled the 
following table. 
Unless the authority is stated in brackets, the observations 
are my own. 
The following notes refer to the table :— 
Note A. Observations taken at Quetta by two persons with stop¬ 
watches over a measured distance varying from 400 to 
660 yards. All birds were below 1000 feet, and in no 
case were they migrating. 
Note B. Observations taken in East Africa in the autumn of 1915 
on migrants by using theodolites on a base of 1200 feet. 
Note O. Observations made at Dar-es-Salaam by a system of two 
persons with stop-watches stationed 440 yards apart and 
timing birds flying between points aligned by two stakes. 
All observations taken on still evenings when birds were 
flying to and from their breeding-grounds. 
Note D. Observations made near Rafa in southern Palestine during 
the autumn of 1917 by means of theodolites at two anti¬ 
aircraft gun-stations on a base of 8926 feet, the stations 
being connected by telephone. 
