CHIMNEY SWIFT 27 



plished it by building a miniature chimney, a 

 wooden shaft eighteen inches square and six feet 

 high, on top of a flat tower where he could look 

 down on the birds at will. It is encouraging to 

 read that it was occupied the day after it was 

 completed. In studying his tenants, Mr. Wid- 

 mann found that the birds cannot build in damp 

 weather, as the glue must have dry air to harden 

 in. As only a small amount of this glue is 

 secreted daily, nest-building, with the interrup- 

 tions of rainy days, sometimes takes nearly three 

 weeks. One pair of Mr. Widmann's birds spent 

 two days in laying their foundation, besmearing 

 the wall and fastening the first sticks to it. When 

 the first egg was laid, ten days later, the nest was 

 only half done, and from that time, curiously 

 enough, building and laying went on together. 

 When the young were two weeks old, Mr. Wid- 

 mann could not find them when he went to the 

 chimney ; but while wondering what had become 

 of them, one of the parents came with food, and 

 he discovered that " all four were huddling side 

 by side, hanging on the wall immediately below 

 the nest and entirely hidden from view above." 

 The next week, Mr. Widmann says, " I was still 

 more surprised when, bending my head over the 

 shaft, the youngsters jumped right against my 

 face with a strong, hissing noise, which I believe 

 must be a very effective means of frightening 

 unsuspecting visitors." When the brood actually 



