In this connection, a brief description may be made of the regular military service of the lord and vassal under the Tokugawa. In the Edo castle, all the officials from the _rōjiu_ downward served in time of peace in civil capacities, but, in war, held military command, the shōgun himself sometimes taking the field. As to the feudal barons in the country, those whose income did not exceed ten thousand _koku_ of rice were required to furnish ten horsemen and two hundred and thirty-five foot-soldiers, with full equipment of bows, guns, spears, banners, and so forth; while those who enjoyed a larger revenue were under obligation to furnish more ample contingents in proportion to their income. The shōgun himself had a large bodyguard, consisting of 30,000 men or upward, as well as a powerful standing force, called _ōbangumi_, which was prepared to take the field first in the event of an emergency. The _samurai_ of these troops discharged civil duties in times of peace. Throughout the various clans a military system closely resembling that of the shōgunate prevailed. To Yoshimune's initiative belongs, also, the establishment of a fire-brigade in Edo. In earlier times, during the period of the fourth shōgun, Iyetsuna, in January, 1657, a conflagration broke out in Edo, reducing nearly one-half of the city to ashes, and entailing the loss of many lives. After this catastrophe, Matsudaira Nobutsuna, who then held the office of _rōjiu_, effected great improvements in the division of the city, repaired and widened the streets, removed the great Buddhist temples to the suburbs, created large spaces to which the citizens could fly for refuge in the event of fire, and built embankments to prevent the overflow of the rivers, thus greatly augmenting the prosperity of the capital. Prior to this three aqueducts had been constructed in the Kanda, Tamagawa, and Senkawa districts, by which means immense facilities were conferred in the matter of water supply. After the fire of 1657, however, the crime of incendiarism became common, and owing to the high winds so often prevailing in Edo, fires thus kindled proved very destructive, as many as ten thousand houses being sometimes ruined at one time. Perpetual exposure to such a destructive agency naturally exercised an injurious effect upon the methods of house construction. The citizens contented themselves with flimsy dwellings, in many cases thatched, not tiled, and the decoration of the nobles' mansions began to be materially reduced. On the other hand, the prosperity of the city increased so greatly that its area extended over twenty-five square miles and its population aggregated two millions. Conflagrations, however, continued as frequent as ever. Yoshimune, therefore, encouraged the people to build houses of stone or other fireproof materials, and in streets of prime importance, like those in the Kanda and Nihonbashi districts, the shōgun did not hesitate to have the houses pulled down