38 



occurrence owing to the growth of the trees. The upper hole has the 

 shape shown in the accompanying illustration, to make the 

 hanging of the boxes more convenient. 



A very great improvement was recently effected by the 

 slope introduced in the angle between the cover and the 

 batten. In spite of all the advantages it was found impossible to prevent 

 rainwater from occasionally entering the interior. This unfortunate 

 state of affairs was especially inevitable when the boxes hung just where 

 the tree formed a gutter a thing that cannot always be avoided, 

 because it is not noticed beforehand. The slope, however, conducts 

 the water that flows down the batten, directly 

 away from the interior of the box, which is kept 

 dry by this means.* If in spite of this the wet 

 penetrates into the interior during heavy down- 

 pours, Baron von Berlepsch has given instruc- 

 tions that a vertical hole of about 3 mm. is to 

 be bored in the trough. This hole is covered 

 and filled up by the mixture mentioned on pp. 

 43-4, but it is quite sufficient to drain off the 

 Screw nail. Key. moisture. Besides, a hole of this description 



corresponds to what we find in the natural hole, where the moisture 

 drains off into the rotten core. 



The opening is sometimes opposite the batten, sometimes at its side. 

 The "screw-nails" which are used to fasten the boxes, are better than 

 ordinary nails, because they need not be driven in so far, and yet are 

 very firm, owing to their peculiar twists. (See illustration.) 



A key is necessary to tighten the screw-bolts of the cover and the 

 batten, which are often loosened in transit, or to enable one to remove 

 the cover in order to see the interior of the box when it is hanging up. 



(See illustration.) 



(E) Kinds of Boxes. 



Five different kinds of Berlepsch's nesting-boxes, resembling each 

 other in construction, but differing in size to correspond with woodpecker 

 holes, are manufactured. f 



* Baron von Berlepsch, much to our satisfaction, has at last consented to patent 

 this and all recent improvements. It will be found only in the nesting-boxes 

 that also bear the trade-mark. (See p. 42.) 



f For prices and particulars as to where these and the other appliances 

 recommended can be obtained, see advertisement pages at the end of this book. 



