Being an unclean bird, and one of ill omen, it was not permitted to perch on the roof of the Temple. According to some writers, it was kept off by means of scarecrows, and according to others, by long and sharp iron spikes set so closely together that there was no room for the bird to pass between them. The latter is by far the more probable account, as the Raven is much too cunning a bird to be deceived by a scarecrow for any length of time. It might be alarmed at the first sight of a strange object, but in a very short time it would hold all scarecrows in supreme contempt. Its carrion-eating propensities were well known to the ancient writers, who must have had many opportunities of seeing the Raven unite with the vultures in consuming the bodies, not only of dead animals, but of warriors killed in battle. So fond was the Raven of this food that, according to those writers, the very smell of human blood attracted the bird; and, if a man accidentally cut himself, or if he were bled for some illness, the odour of the blood would bring round the spot all the Ravens of the place. The punctuality with which the Raven, in common with all its kin, returns to its roosting-place, was also familiar to the Talmudists, who made rather an ingenious use of this habit The ceremonial law of the Jews required the greatest care in observing certain hours, and it was especially necessary to know the precise time which marked the separation of one day from another. This was ascertained easily enough as long as the day was clear, but in case of a dull, murky day, when the course of the sun could not be traced, some other plan was needed. In the olden times, no artificial means of measuring time were known, and the devout Jew was consequently fearful lest he might unwittingly break the law by doing on one day an act which ought to have been done on another. A convenient method for ascertaining the time was, however, employed, and, as soon as the Ravens, rooks, and similar birds were seen returning to their homes, the sun was supposed to be setting. This habit of returning regularly at the same time is mentioned by Mr. Tristram in his "Land of Israel:"-- "Of all the birds of Jerusalem, the raven is decidedly the most characteristic and conspicuous. It is present everywhere to eye and ear, and the odours that float around remind us of its use. On the evening of our arrival we were perplexed by a call-note, quite new to us, mingling with the old familiar croak, and soon ascertained that there must be a second species of raven along with the common _Corvus corax_. This was the African species (_Corvus umbrinus_, Hed.), the ashy-necked raven, a little smaller than the world-wide raven, and here more abundant in individuals.