on the Eddy stone. 257 
The last of the night-movements daring my visit was one 
of considerable magnitude and remarkable interest. It 
set in on the night of October loth, 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-influences 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-Petrels were observed — the 
SER. VIII. VOL. II. s 
