230 Col. K. Meinertzliagen on the [Ibis, 



arrive in such numbers on our central east coast. The 

 Bluethroat estimate is based ou the assumption that birds 

 fly direct from Egypt to Heligoland in one nigiit, which is 

 certaiuly not the case. His estimate of the flight of Godwit 

 and C'Urlew, on \yhich 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 fliglit. 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 leavinsr Kent 

 at (hiwn they would be in Portiigai 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 iu brackets, the observations . 

 are my own. 



The following notes refer to the table : — 



Note A, Observations taken at Quetta b_y 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'. 



NoTR B. Observations taken in East Africa in the autumn of 1915 

 on migrants by using theodolites on a base of ll!00 feet. 



NoTK C. Observations made at Dar-es-Salaaui bj a system of two 

 persons with stop-watches stationed 440 yards apart f.nd 

 timing birds fljing 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 Rata in sonthern Palestine during 

 the autumn of ]917 by means of theodolites at two anti- 

 aircraft gun-stations on a base of 3926 feet, the stations 

 being connected by telephone. 



