igii- Barrington. — Push of Birds on March 2gth-2,oih 107 



called a " combination of coincidences." The " Wonderful 

 Battell of the Birds," described in the Cork Archaeological 

 Journal as having taken place between the 12th and 14th 

 of October, 1621, may have been due to an analogous cause. 



It is a well-known ornithological axiom that birds, in 

 the Northern Hemisphere, usually breed in the most 

 northerly portion of their range. Immense numbers annually 

 towards the end of March move northwards through Spain 

 and France to their breeding haunts. This year, for weeks 

 previous to the 29th of that month, cold northerly or easterly 

 winds prevailed over France and the British Isles, and 

 birds though desirous to migrate were held back by the 

 weather, and many species, which would otherwise have 

 travelled separately, collected in the South of Europe like 

 passengers at a railway station, anxious to proceed upon 

 their journey, but unable to do so owing to a breakdown 

 on the line. 



To this cause I attribute the extraordinary number of 

 birds, and as the temperature was much milder on the west 

 coast of France and in Brittany than in central France, 

 they took a more westerly course than usual, unwilling 

 to face the bitter N.E. winds. 



The following tables, compiled from the daily weather- 

 charts, show the direction of the wind at the mouth of the 

 Channel, and the fluctuations of temperature over central 

 France for ten da3^s previous to the 29th March. 



In Table I. it will be seen that the wind was almost 

 continuously N. or E., but that it suddenly changed to the 

 S. at Valentia, Pembroke and ^the Scilly Islands on the 

 morning of the 29th ; and Table II. shows that the 

 aggregate rises of temperature at ten French stations on 

 that day amounted to 73 degrees, or an average of over 

 7 degrees at each station. This favourable change, coupled 

 with a southerly wind in the mouth of the Channel, so to 

 speak, liberated the birds, and as the wind still continued 

 N.E. and E. over England, they decided to take a longer 

 and more exhausting course than usual and travel towards 

 Ireland and then turn N.E. 



