_b._ The means by which Servius gave the Plebeians a share in the government was by establishing a new Popular Assembly, in which Patricians and Plebeians alike voted. It was so arranged that the wealthiest persons, whether Patricians or Plebeians, possessed the chief power. In order to ascertain the property of each citizen, Servius instituted the _Census_, which was a register of Roman citizens and their property. All Roman citizens possessing property to the amount of 12,500 asses and upward[7] were divided into five great _Classes_. The First Class contained the richest citizens, the Second Class the next in point of wealth, and so on. The whole arrangement was of a military character. Each of the five Classes was divided into a certain number of Centuries or Companies, half of which consisted of Seniores from the age of 46 to 60, and half of Juniores from the age of 17 to 45. All the Classes had to provide their own arms and armor, but the expense of the equipment was in proportion to the wealth of each Class. The Five _Classes_ formed the infantry. To these five Classes were added two centuries of smiths and carpenters, and two of trumpeters and horn-blowers. These four centuries voted with the Classes. Those persons whose property did not amount to 12,500 asses were not included in the Classes, and formed a single century. At the head of the Classes were the Equites or cavalry. These consisted of eighteen centuries, six being the old patrician Equites, as founded by Romulus and augmented by Tarquinius Priscus, and the other twelve being chosen from the chief plebeian families.[8] The Centuries formed the new National Assembly. They mustered as an army in the Campus Martius, or the Field of Mars, on the banks of the Tiber, outside the city. They voted by Centuries, and were hence called the _Comitia Centuriata_. Each Century counted as one vote, but did not consist of the same number of men. On the contrary, in order to give the preponderance to wealth, the first or richest class contained a far greater number of Centuries than any of the other classes (as will be seen from the table below), although they must at the same time have included a much smaller number of men. The Equites and First Class alone amounted to 100 Centuries, or more than half of the total number; so that, if they agreed to vote the same way, they possessed at once an absolute majority. An advantage was also given to age; for the Seniores, though possessing an equal number of votes, must of course have been very inferior in number to the Juniores.