SWALLOWS AND SWIFTS 155 



early afternoon in June or July, when the silver in the ther- 

 mometer rises towards eighty degrees, and the heat grows 

 drowsy on the lower levels trodden by men. They scream 

 about our heads with a note of triumph in such sunshine, and 

 betray the ties with the south that call them so early away. 

 They have a still more characteristic flight in the serene and 

 windless evenings when the afterglow pervades the height of 

 the sky, and the glow-worms burn to their very reddest under 

 the hedges. Then the swifts float in troops high in air, until 

 the gathering darkness hides them ; often several descend 

 close to earth in pursuit of each other, and again shoot 

 upwards into the vault like scraps of charred paper in the 

 draught of a great fire. Since they often ride so high and 

 so equably in the falling night, the idea prevails that they 

 actually rest all night on the wing, gliding with the minimum 

 of effort against the light currents of summer air. But this 

 is merely a fancy, bred of their buoyant flight, and the fact 

 that they are not seen to return to their nesting-places under 

 the roof. There is little doubt that they slip quietly in after 

 it is too dark to see them descend. 



If swifts slept or rested all night on the wing, we should 

 see them afloat above us as soon as it grows light on mid- 

 summer mornings. But this is not the case ; they do not begin 

 their noisy morning flights until the sunlight is strong, and 

 the veil of mist is melted. They are not nearly such early 

 birds of a morning as the swallow. Swallows are often astir 

 before sunrise, in the same dewy hour of twilight when the 

 industrious bumble-bee makes a buzzing on the fringe of the 

 scabious or the lip of the honeysuckle where he bivouacked 

 under the sky. Then the chuckling song of the swallow 

 often streams down from the ridge of the roof, or the vane 

 of the stable weathercock, or some bare and jutting twig of 

 a walnut or apple tree. Heard thus in solitude, it sounds 



