[9] In another experiment (No. 37), Hero shows “how temple doors may be opened by fire on an altar.” He says, “Let the proposed temple stand on a pedestal, on which is also a small altar. Through the altar insert a tube, of which one mouth is within the altar, and the other nearly at the centre of a globe. The tube must be soldered to the globe in which a bent syphon is placed. Let the hinges of the doors be extended downwards, turning freely on pivots, and from the hinges let two chains running into one be attached by means of a pulley to a leaden weight, on the descent of which the doors will be shut, let the outer leg of the syphon bend into a suspended vessel and fill the globe half full of water. When the fire becomes hot, the heated air in the altar expands and, passing through the tube into the globe, will drive the liquid through the syphon into the suspended vessel which, descending by its weight, will tighten the chains and open the doors.” [10] Although there may be a doubt how far the inventions recorded by Hero were used for superstitious practices, there is no question that, somewhat later, the agency of steam was employed for purposes anything but legitimate. Thus Gibbon (c. xl.) gives an amusing account of how Anthemius, the architect of Sta. Sophia at Constantinople, avenged, himself on Zeno, the orator. “In a lower room,” says he, “Anthemius arranged several vessels or cauldrons of water, each of them covered by the wide bottom of a leathern tube, which rose to a narrow top, and was artificially conveyed among the joints and rafters of the adjacent building. A fire was kindled beneath the cauldron; the steam of the boiling water ascended through the tubes; the house was shaken by the effects of imprisoned air, and its trembling inhabitants might wonder that the city was unconscious of the earthquake they had felt.” Still later, Arago, in his “Éloge de James Watt,” notices an ancient Teutonic god, called _Bustarich_, on the banks of the Weser, who was made by the priests to show his displeasure through the agency of steam. The head of the metal God was hollow and had within it a pot of water. Its mouth and another hole having been plugged, a charcoal fire was cleverly lighted under it, in such a way as not to be perceived by the expectant worshippers. After a while, the imprisoned steam forced out the plugs, with a loud report, followed by two jets of steam, which formed a dense cloud round the god and concealed him from his astonished worshippers. [11] Paper read at the Society of Arts 14th of April, 1858, by John MacGregor, Esq., Barrister at Law. [12] This work in Latin, printed at Verona, 1472, is the first book with woodcuts printed in Italy. [13] This letter is written from Simancas, and bears the date 27th August, 1825. It was published 1826, in Lack’s “Astronomical Correspondence.”