The principal Weight in use among the Romans, was the pound, called As or Libra, which was equal to 12 oz. avoirdupoise, or 16 oz. 18 pwts. and 13¾ grains, troy weight. It was divided into twelve ounces, the names of which were as follow: Uncia, 1 oz.—Sextans, 2 oz.—Triens, 3 oz.—Quadrans, 4 oz.—Quincunx, 5 oz.—Semis, ½ lb.—Septunx, 7 oz—Bes, 8 oz.—Dodrans, 9 oz.—Dextans, 10 oz.—Deunx, 11 oz.

The As and its divisions were applied to anything divided into twelve parts, as well as to a pound weight. The twelth part of an acre was called Uncia and half a foot, Semis, &c.

The Measures for Things Dry.—Modius, a peck—Semimodius, a gallon—Sextanus, a pint—Hemina, one-half pint, and 3 smaller measures, for which we have not equivalent names in English. One Modius contained 2 Semimodii—each Semimodius contained 8 Sextarii—each Sextarius, 2 HeminÆ—each Hemina, 4 Acetabula—each Acetabulum, 1½ Cyathi—each Cyathus—4 LigulÆ.

The Liquid Measures of Capacity were the Culeus, which was equal to 144½ gallons—it contained 20 AmphorÆ or Quadrantales—each Amphora, 2 UrnÆ—each Urna, 4 Congii—each Congius, 6 Sextarii—and each Sextarius, 2 Quartarii or naggins—each Quartarius, 2 HeminÆ—each Hemina, 3 Acetabula or glasses—each Acetabulum, 1½ Cyathi—and each Cyathus, 4 LigulÆ.

The Measures of Length in use among the Romans were, Millarium or Mille, a mile—each mile contained 8 Stadia, or furlongs—each Stadium, 125 Passus—each Pace, 5 feet.

The Pes, or foot, was variously divided. It contained 4 Palmi or handbreadths, each of which was therefore 3 inches long—and it contained 16 Digiti, or finger breadths, each of which was therefore three-quarters of an inch long—and it contained 12 UnciÆ, or inches: any number of which was used to signify the same number of ounces.

Cubitus, a cubit, was 1½ feet long—Pollex, a thumb's breadth, 1 inch—Palmipes, a foot and hand's breadth, i.e. 15 inches long—Pertica, a perch, 10 feet long—the lesser Actus was a space of ground 120 feet long by four broad—the greater Actus was 120 feet square—two square Actus made a Jugerum, or acre, which contained therefore 28,000 square feet.

The first money in use among the Romans was nothing more than unsightly lumps of brass, which were valued according to their weight. Servius Tullius stamped these, and reduced them to a fixed standard. After his reign, the Romans improved the old, and added some new coins. Those in most frequent use, were the As, Sestertius, Victoriatus, Denarius, Aureus.

The As was a brass coin, stamped on one side with the beak of a ship, and on the other with the double head of Janus. It originally weighed one pound; but was afterwards reduced to half an ounce, without suffering, however, any diminution of value. It was worth one cent and forty-three hundredths.

Sestertius was a silver coin, stamped on one side with Castor and Pollux, and on the opposite with the city. This was so current a coin, that the word Nummus, money, is often used absolutely to express it. It was worth three cents and fifty-seven hundredths.

Denarius was a silver coin, valued at ten asses; that is, fourteen cents and thirty-five hundredths of our money. It was stamped with the figure of a carriage drawn by four beasts, and on the other side, with a head covered with a helmet, to represent Rome.

Victoriatus was a silver coin, half the value of a Denarius. It was stamped with the figure of Victory, from whence its name was derived. Being worth five Asses, it was called Quinarius.

Libella, Sembella, Teruncius, were also silver coins, but of less value than the above. Libella was of the same worth as the As—Sembella was half a Libella, equal to seventy-one hundredths of a cent—and the Teruncius was half of a Sembella.

Aureus Denarius was a gold coin, about the size of a silver Denarius, and probably stamped in a similar manner. At first, forty Aurei were made out of a pound of gold; but under the Emperors it was not so intrinsically valuable, being mixed with alloy.

The value of the Aureus, which was also called Solidus, varied at different times. According to Tacitus, it was valued and exchanged for 25 Denarii, which amounted to three dollars, fifty-eight cents and seventy-five hundredths.

The Abbreviations used by the Romans to express these various kinds of money, were, for the As, L.—for the Sesterce, L. L. S. or H. S.—for the Quinary, V. or λ.—for the Denarius, X. or :!:

Sesterces were the kind of money in which the Romans usually made their computations.—1,000 Sesterces made up a sum called Sestertium, the value of which in our money, was thirty-five dollars and seventy cents.

The art of reckoning by Sesterces was regulated by these rules:

First—If a numeral adjective were joined to Sestertii, and agreed with it in case, it signified just so many Sesterces; as decem Sestertii, 10 Sesterces—thirty-five cents and seven tenths.

Second—If a numeral adjective, of a different case, were joined to the genitive plural of Sestertius, it signified so many thousand Sesterces; as decem Sestertium, 10,000 Sesterces—$357.

Third—If a numeral adverb were placed by itself, or joined to Sestertium, it signified so many hundred thousand Sesterces; as Decies, or decies Sestertium, 1,000,000 Sesterces—$35,700.

Fourth—When the sums are expressed by letters, if the letters have a line over them, they signify also so many hundred thousand Sesterces: thus, H. S. M̅. C̅.—denotes the sum of 1,100 times 100,000 Sesterces, i.e. 110,000,000—nearly $4,000,000.