The Use of a Blind in the Study of Bird -Life 25r 



The Umbrella. — The umbrella employed in making 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 importance when 

 one spends hours in the little structure on beach or marsh, where it is fully 



UMBRELLA BLIND SET NEAR WARBLING VIREO'S NEST 

 In this blind an ordinary umbrella was employed, the covering being sewed to the edge 

 (Shoal Lake, Man., June, iooi) 



exposed to the sun. The "stick" of this umbrella is a metal tube without the 

 usual wooden handle. 



The Supporting Rod. — The umbrella is supported by two brass tubes each 

 of the same length as the umbrella, or thirty-three inches. The larger is shod 

 with a steel point, by the insertion of a small cold chisel or nail punch, which 

 is brazed in position. It can then be readily driven into the ground. At the 

 upper end, a thumb-screw is placed. The smaller tube should enter the larger 

 snugly and should, in turn, be just large enough to receive the umbrella rod, 

 which will enter it as far as the spring "catch". The height of the umbrella 

 may therefore be governed by the play of the smaller tube in the larger, while 

 the thumb-screw will permit one to maintain any desired adjustment; as one 

 would fix the height of a music rack. 



The Covering. — If the blind is to be used about home, a light denim may 

 be employed; if it is to see the harder service of travel and camp-life, a heavier 

 grade of the same material will be found more serviceable. In the former case, 

 the denim may be sewed to the edge of the umbrella, which then has only to be 



