"This law, which has thus far perplexed scientists, is that the heavier and bigger the bird or insect, the less relative wing area is required for its support. Thus the area of wing surface of a gnat is forty-nine units of area to every one of weight. In graphic contrast to that, a condor (_Sarcorhamphus gryphus_) which weighed 16.52 pounds had a wing surface of 9.80 square feet. In other words, though the gnat needs wing surface in a ratio of forty-nine square feet per pound of weight, a great condor manages to sail along majestically with .59 of a square foot to at least a pound of weight. The unexplained phenomenon persists consistently throughout the whole domain of entomology and ornithology. Going up the scale from the gnat, it is found that with the dragon fly this ratio is 30 to 1, with the _tipula_, or daddy-longlegs, 14.5 to 1, the cockchafer only 5.15 to 1, the rhinoceros beetle 3.14 to 1. "Among birds the paradoxical law that the smaller the creature the bigger the relative supporting wings holds good. A screech owl (_Scops zorca_) weighing one-third of a pound had 2.35 square feet of wing surface per pound of weight. A fish hawk (_Pandion haliaetus_) weighing nearly three pounds had a wing area of 1.08 square feet to each pound. A turkey buzzard weighing 5.6 pounds had a little less than one square foot of wing surface to each pound. A griffon vulture (_Gyps fulvus_) weighing 16.52 pounds had a wing surface of only .68 square feet to the pound. "Students of aerial navigation who are devoting much attention to observations of birds say that if the peculiar law governing extant flying creatures could be fathomed the problem of human flight might be solved." A BIRD'S FOOT You will agree with me, after you have studied a bird's foot, that it is one of Nature's most wonderful contrivances, so admirably adapted for the purposes to which it is devoted that one cannot help feeling that a Divine Mind must have planned it, just as a man would make a watch for the express purpose of keeping time. But what is properly included in a bird's foot? Here we shall have to correct a popular mistake, if we wish to be accurate, in the scientific sense of the term. Most people think that the avian foot consists only of the toes and claws, or the part that comes in direct contact with the ground or the perch. That, however, is an error, for the foot really comprises, in addition to the toes and claws, the first long bone of the limb, reaching from the base of the digits to the first joint. You will see, therefore, that the bird walks on its toes, not on its foot as a whole.