Wool, however, was the most common material, and the velaria made in Apulia were most esteemed, on account of the whiteness of the wool.
Those who are not acquainted by experience with the difficulty of giving stability to tents of large dimensions, and the greater difficulty of erecting awnings, when, on account of the purpose for which they are intended, no support can be applied in the centre, may not fully estimate the difficulty of erecting and managing these velaria. Strength was necessary, both for the cloth itself and for the cords which strained and supported it, or the whole would have been shivered by the first gust of wind, and strength could not be obtained without great weight. Many of our readers probably are not aware, that however short and light a string may be, no amount of tension applied horizontally will stretch it into a line perfectly and mathematically straight. Practically the deviation is imperceptible where the power applied is very large in proportion to the weight and length of the string. Still it exists; and to take a common example, the reader probably never saw a clothes-line stretched out, though neither the weight nor length of the string are considerable, without the middle being visibly lower than the ends. When the line is at once long and heavy, an enormous power is required to suspend it even in a curve between two points; and the amount of tension, and difficulty of finding materials able to withstand it, are the only obstacles to constructing chain bridges which should be thousands, instead of hundreds of feet in length.
In these erections the piers are raised to a considerable height, that a sufficient depth may be allowed for the curve of the chains without depressing the roadway. Ten times—a hundred times the power which was applied to strain them into that shape would not suffice to bring them even so near to a horizontal line but that the most inaccurate and unobservant eye should at once detect the inequality in their level; and the chains themselves would probably give way before such a force as this could be applied to them. The least diameter of the Coliseum is nearly equal in length to the Menai bridge; and if the labor of stretching cords over the one seems small in comparison with that of raising the ponderous chains of the other, we may take into consideration the weight of cloth which those cords supported, and the increase of difficulties arising from the action of the wind on so extensive a surface.
In boisterous weather, as we learn from Martial and other authors, these difficulties were so great that the velum could not be spread. When this was the case the Romans used broad hats, or a sort of parasol, which was called umbella or umbraculum, from umbra, shade. We may add, in conclusion, that Suctonius mentions as one of Caligula's tyrannical extravagances, that sometimes at a show of gladiators, when the sun's heat was most intense, he would cause the awning to be drawn back, and, at the same time, forbid any person to leave the place.
The difficulty of the undertaking has given rise to considerable discussion as to the means by which the Romans contrived to extend the velum at such a height over so great a surface, and to manage it at pleasure. Sailors were employed in the service, for the Emperor Commodus, who piqued himself on his gladiatorial skill, and used to fight in the arena, believing himself mocked by the servile crowd of spectators, when once they hailed him with divine honors, gave order for their slaughter by the sailors who were managing the veils.
COLISEUM OF ROME.[ToList]
Concerning the method of working them no information has been handed down. It is evident, however, that they were supported by masts which rose above the summit of the walls. Near the top of the outer wall of the Coliseum there are 240 consoles, or projecting blocks of stone, in which holes are cut to receive the ends of spars, which ran up through holes cut in the cornice to some height above the greatest elevation of the building. A sufficient number of firm points of support at equal intervals was thus procured; and, this difficulty being overcome, the next was to stretch as tight as possible the larger ropes, upon which the whole covering depended for its stability.
The games to which these buildings were especially devoted were, as we have already hinted, two-fold—those in which wild beasts were introduced, to combat either with each other or with men, and those in which men fought with men. Under the general term of gladiators are comprised all who fought in the arena, though those who pitted their skill against the strength and ferocity of savage animals were peculiarly distinguished by the name of bestiarii. In general these unhappy persons were slaves or condemned criminals, who, by adopting this profession, purchased an uncertain prolongation of existence, but freemen sometimes gained a desperate subsistence by thus hazarding their lives; and in the decline of Rome, knights, senators, and even the emperors sometimes appeared in the arena, at the instigation of a vulgar and degrading thirst for popular applause.