on the Eddy stone. 257 



The last of the ni^ht-raovemGnts during my visit was one 

 of considerable magnitude and remarkable interest. It 

 set in on the night of October 15th, and was in progress 

 until nearly daybreak of the following morning. The meteoro- 

 logical conditions under which it was witnessed were 

 exceptional, and afforded a clear and unmistakable demon- 

 stration of the effect of weather-inHuences and the extent to 

 which we are dependent thereon for rendering the obser- 

 vation of migratory movements possible. In this important 

 respect it was one of the most valuable experiences that I had. 

 The night was bright and starlight until 7.30 p.m.; but from 

 that hour until daybreak the state of the atmosphere was ever 

 oscillating between intervals of brightness and those during 

 which the sky was overcast with a slight degree of haziness, 

 rendering the Breakwater Light at Plymouth invisible, and 

 full power necessary at the Eddystone. The wind was 

 E.N.E. and varied in force from a moderate to a gentle 

 breeze. After a little experience it became possible to tell, 

 by watching the beams of light, what the atmospheric con- 

 ditions of the moment and the chances of observation were. 

 The beams grew conspicuous when the sky became overcast 

 through the presence of moisture in the atmosphere, and 

 then the birds immediately approached the beacon; but as 

 soon as this condition passed away the rays at once thinned 

 down and became little more than visible, the birds sheared 

 off, and the movement in progress ceased to be observed. 

 During the duration of the periods favourable for obser- 

 vation, between 7.35 p.m. and midnight, the following species 

 were observed : — Song-Thrushes, Mistle-Thrushes, Redwings, 

 Skylarks, Goldcrests, Starlings (first at 10.30), Blackbirds 

 (11.30), Wheatears (11.45), Grey Wagtail, and Stonechats 

 (midnight) . At 9.40 a number of Waders passed, but their 

 calls were in an unknown tongue. The period between 

 11.15 P.M. and midnight was the most productive of results. 

 At intervals between 1 a.m. and daybreak Wagtails, Mistle- 

 Thrushes, Goldcrests, Starlings, Larks, Wheatears, Wrens 

 (1.15 a.m.), Song-Thrushes, Meadow-Pipits (2.30 a.m.), Red- 

 wings, Blackbirds, and Storm-Pctrcls were observed — the 



SER. VIII. VOL. II. s 



