THE OBSERVATION BLIND 11 
explained. If you wish to maké a record of some length concerning a 
certain species, place a cross or asterisk in its square. This refers to 
your journal of the same date which is entered on the horizontally 
ruled sheets following those used for the roll-call. 
Read from left to right, such a roll-call gives in a graphic, condensed 
form the standing of a species during the period of observation. Read 
from the top to the bottom of the page, it gives, in an easily comparable 
way, the complete record of each day, and, at the same time, it becomes 
an index to the bird-notes in the journal, which follows. 
To prevent needlessly multiplying these roll-call sheets, the series 
of birds’ names should be made to last at least during an entire season. 
To this end do not completely fill the right-hand page, but when you 
have used all of it but a space equal in width to the space occupied by 
the column of birds’ names on the left side of the left page, cut this 
part of the page—the extreme right—off; the part remaining will, 
when turned over to the left, just meet the column of names, and the 
lines of this column and of the new page will thus run continuously. As 
before remarked, the roll-book should be attended to immediately on 
returning from the field, while your impressions are fresh. The journal 
may if necessary wait, when a reference to the roll-call will aid in 
recalling the day’s experiences. Only 
one cover, with clasps for the reten- 
tion of the perforated sheets, will be 
needed, and at the end of a trip or 
season the sheets may be removed and 
bound. This is essentially the method 
of note-keeping described in the first 
edition of the “Handbook” and which, 
after seventeen years’ additional use, 
I still unreservedly recommend. 
The Observation Blind—The ob- 
servation blind which, during the past 
ten years, has met the demands of 
many and varied situations, is in brief 
an umbrella opened within a bag 
long enough to conceal one. It is 
described in my “(Camps and Cruises 
of an Ornithologist” (p. xiii) as 
follows: 
“The umbrella employed in mak- 
ing an observation blind is known to 
the trade as a ‘sign’ umbrella. It 
agrees with the normal variety in size 
but differs from it in having a, large 
hole in the center. This permits a | 
current of air to pass through the ‘ 
blind—a matter of the first import- = Sido cethe umpetia bua 
