However this may be, I had no sooner reached the part of the Rock tenanted by the Petrels than I was given the most surprising evidence of their activity during the night. From the ground at my feet and on every side there issued the uncanny little song—if I may so call it—of birds doubtless sitting at the mouths of their burrows. It was not like the cry of a sea bird, but a distinctly enunciated call of eight notes, possessing a character wholly its own, and not to be compared to the notes of any bird I have ever heard, though at the time it impressed me as having a certain crowing quality. Such a call might be uttered by elves or brownies. Occasionally I saw a blur of wings as a bird passed between me and the lighthouse. [Illustration: 99. Gannets on nests.] Later, the fog, which had been scudding over us in wisps and ribbons, closed in, and through the medium of a guncotton bomb the Rock gave notice of its presence to the mariners who might be in the surrounding waters. Captain Taker heard the dull, booming voice as with disappointing promptness he came to take us from the Rock, and early in the morning we heard his fog horn from the gray bank below telling where the Sea Gem, as yet unseen, was anchored. In the hope of better weather I deferred photographing the Gannets, the only accessible colony of which was on the north side of the Rock; but forced now to make the best of the existing conditions, I took the twin-lens, fastened one end of a rope about my waist, and gave the other end to Captain Bourque, in order that, unhampered by thought of fall, I might creep along the slippery ledges where the birds nested.^{99} The fog had lifted, but the day was gloomy, and only the white plumage of the birds and a wide-open lens yielded successful photographs. It was my first visit to the big white birds, who, in spite of persecution, have as yet acquired but little fear of man, and as with hoarse croaks and a dashing of wings they pitched onto the narrow ledges near me, their size and boldness, in connection with my somewhat insecure footing, aroused in me a feeling which I had not experienced when surrounded by the smaller Murres, Auks, and Puffins. The main nesting ledge was out of reach below, but small groups of birds were nearer, and these I photographed at a distance of about ten feet.^{100} These Gannets are magnificent birds, and when on the wing exhibit a combination of power and grace excelled by no other bird I have seen. They are most impressive when diving, as with half-closed wings, like great spearheads, they descend from a height of about forty feet with a force and speed that takes them wholly out of sight, and splashes the water ten feet or more into the air. Cory graphically compares the sight of a distant flock of Gannets diving at a school of fish, to a continuous stream of beans poured from a pail. [Illustration: 100. Gannet on nest. Two nests in foreground.]