In the treatise “On Rivers,” attributed to Plutarch, a stone is said to have been found on Mount Cronius, which bore the name of “cylinder.” When Jupiter thundered, this stone, terrified by the noise, rolled down from the top of the mountain.[153] This passage is interesting as suggesting one of the reasons which caused the name “thunderbolt” to be given to certain stones, for stones adapted to ornamental use might easily be exposed by the weathering of the rocks, and then detached by the concussion produced by heavy thunder. Of course, the cylinder-stone here mentioned must have more especially signified one of the prehistoric celts, but it is not unlikely that the name was also given to other, unworked stones, having a similar form. Before Galba was chosen emperor, and when he was acting as governor of the Basque provinces in Spain, a thunderbolt descended upon the shore of a lake in that region. Search was made for the stones which were supposed to have fallen, and Suetonius tells us that twelve axes were found. This was regarded as a sure augury of Galba’s elevation to the imperial dignity,[154] but for the archaeologist the presence of the axes merely signifies that this was the site of a lake dwellers’ village. In some cases, the stone which was held to be a dwelling-place of the divinity was also regarded as a representation, or epitome, of some sacred mountain. In the earliest stage of this belief, the god was supposed to have his abode in the mountain, and later he was thought to animate the stone which had a fancied likeness in shape to the mountain. A coin of the Roman emperor Elagabalus (204–222 A.D.)[155] bears on its reverse a representation of one of the sacred stones of Astarte, namely, that worshipped at Sidon. This is shown resting upon a car, and it seems probable that it was transported from place to place, so that large numbers of people could have the privilege of paying reverence to it. There seems to be fairly strong reasons for the belief that the Black Stone of the Kaaba at Mecca is an aerolite.[156] If the conjecture be correct, this stone occupies a unique place among meteoric masses, for it was an object of worship for many centuries before the advent of Mohammed, and is to-day regarded with the highest reverence by one hundred and twenty millions of Mohammedans. One of the most solemn acts performed by the pilgrims at Mecca is the kissing of the Black Stone, and should any one doubt that true religious enthusiasm is aroused by this act, he should read the following words of Ibn Batoutah:[157] The eyes perceive in it a wonderful beauty, similar to that of a young bride; in kissing it one feels a pleasure that delights the mouth, and whoever kisses it wishes he might never cease to do so; for this is an inherent quality in it and a divine grace in its favor. Let us only cite the words of the Prophet in this connection: “Certainly it is the right hand of God on earth.”