1841.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



299 



makes subsidiary ; and tluis its claims to criticism are as strong and 

 as important, as tlie noble art of the painter, or the sculptor. Having 

 then endeavoured to state that architecture is equal to the other arts, 

 in its claims to liberjl criticism, I shall reserve it for my next to show 

 the origin cf its eflects upon the mind, by a definition of that faculty, 

 inherent in us, by which we extract emotion from attitude, proportion 

 and position, even when these three essentials have no counterpart in 

 nature. 



Frederick East. 

 August, 1S41. 



ENGINEERING WORKS OF THE ANCIENTS, No. S. 



DiONYSius of Halicaniassus who lived in the time of Augustus, is 

 the next author who contributes to our series, having extracted from 

 his Roman Antiquities the following accounts of Roman works. 



BRIDGE OVER THE TIBER. 



Ancus Marcius, the 4th King of Rome (B. 3, ch. H,) is said to have 

 been the first who built over the Tiber the famous wooden bridge, 

 which is considered as sacred. It must only be made of wood, and 

 neither iron nor copper may be used in it. When any damage occurs 

 it is the duty of the pontitfs to see to the repair, and to perform cer- 

 tain sacrifices prescribed by law during the progress of the-works. 



Ancus Marcius greatly enlarged the city of Rome, and built the port 

 of Ostia at the mouth of the Tiber. 



Tarquinius Priscus, the 5th King TB. 3, ch. 20), built the walls of 

 Rome of large squared stones, and commenced the sewers, by which 

 the waters are collected in the streets of the city, and carried into the 

 Tiber. The work is admirable, and beyond anything that can be said. 

 For my own part, I believe that Rome has nothing more magnificent, 

 nothing which better shows the grandeur of her empire, than her 

 aqueducts, streets, paved roads, and sewers ; I judge thus not only on 

 account of their utility, but still more on account of the immense out- 

 lay which they have required. To prove what I assert, I will only 

 instance the sewers. According to Caius Aquilius, having been for 

 some time so neglected that they were stopped up, the censors concluded 

 a bargain with a contractor to clean and repair them for a thousand 

 talents. 



We cannot pass over this tribute of the old historian without re- 

 marking that while the temples of Greece are scattered in ruins, and 

 their proudest ornaments become the trophies of barbarians, the roads, 

 aqueducts, and sewers of the Romans still minister to the wants of 

 nations, centuries after the power of their founders has ceased to exist. 

 The English emulate the Romans in the useful nature of their enter- 

 prises, and we trust that the labours of our engineers may minister as 

 long to the service of the world as those of their predecessors. 



GREAT circus. 



Tarquin also embellished the Great Circus between the Aventine 

 and Palatine mounts, and was the first who constructed around this 

 circus covered seats, whereas the practice formerly was to place 

 scaffolding around. 



TARQUINIUS StJPERBUS. 



Tarquin the Proud (B. 4, ch. 10,) the seventh and last king of 

 Rome, employed the people on the public works iu order to occupy 

 them and prevent them from plotting. He continued to the Tiber the 

 sewers begun by his grandfather, and carried out several of bis un- 

 finished works. 



STRABO. 



Having thus dismissed Dionysius of Halicarnassus, we come to 

 Strabo, one of the most celebrated of the geographical writers of the 

 ancients, and from whom, as from Diodorus Siculus, much information 

 is to be gleaned as to ancient mining, a most important branch of engi- 

 neering, as bearing upon earthworks. We shall first take the third 

 book. 



mines in SPAIN. 



A chain of mountains, (the Sierra Morena), parallel to the Betis 

 (Guadalquivir) extends towards the north, approaching more or less 

 the banks of the river ; it contains a great many mines. Silver is 

 found every where in the neighbourhood of lli|)0 and Old and New 

 Sisapone (Almaden). Near the pace called Cotinas, gold and copper 

 are worked together. The mountains on the banks of the Anas (Gau- 

 diana) also contain mines.* 



* B. 3. ch. 2. 



From Turdetania is exported cinnabar equal to that of Sinope. 

 There is also found fossil salt.* 



What renders Turdetania particularly remarkable is its excellent 

 mines. In fact all Iberia is full of them ; but Turdetania unites all the 

 advantages of a mining country to a degree which surpasses any 

 praise. In no country in the world do we find gold, silver, copper and 

 iron in such quantity or of similar quality. Gold is obtained not only 

 from the mines but also from the rivers and streams, in which it is 

 contained mixed with sand. It is also to be found in many dry places, 

 but with this difference, that in these it cannot be distinguished at 

 sight, whilst it shines when covered with the water. This is the 

 reason why water is made to pass over sandy placfts, to make the par- 

 ticles of gold shine. Wells also are dug, and many means have been 

 invented for separating the gold from the sand by washing, so that 

 there are more gold washing works in the country than mines. The 

 Gauls assert that their mines, as well those of the Cevennes as those 

 of the Pyrenees situated on their side, are better ; but, nevertheless, 

 the mines on tlie Spanish side are generally more esteemed. Among 

 the particles of gold are sometimes lumps of gold weighing half a 

 pound, which are named pales, and require very little refining. In 

 cutting stones of ore, small lumps of this metal are sometimes found. 

 After having roasted the gold intended to be purified, by means of an 

 aluminous earth mixed with it, the result of the operation is the alloy 

 of gold and silver known under the name of tkctnun. It is again 

 placed in the fire, ndiich separates the silver, and leaves the gold 

 pure ; for this latter metal is easily fused, and is not of much hardness. 

 It is also fused sooner by the flame of straw, which, being milder, 

 agrees better vidth the nature of gold, which obeys its action, and dis- 

 solves easily, while charcoal, being stronger, consumes a great part by 

 liquefying it too soon, and converting it into vapour. As to the beds 

 of rivers, the particles are extracted, washed in buckets, or in wells or 

 holes made near, and the earth is washed. The furnaces for melting 

 silver are generally made higher, to enable the pernicious vapour of 

 this metal to rise and be dispersed. Some mines of copper have the 

 name of gold mines, whence it is presumed that they formerly supplied 

 this metal. 



Posidonius, in speaking of the number and excellence of these 

 mines, uses ail the exaggerations of an enthusiast. The Turdetanians, 

 says he, use the greatest industry and labour in digging winding gal- 

 leries far into the earth, and often in draining, by means of Egyptian 

 spirals, the subterranean streams with which they meet. But their 

 lot, he observes, is very different from that of the miners of Attica, to 

 whom may be applied the ancient enigma, "They have not taken all 

 that they have drawn from the earth, and they have left there what 

 they possessed." The Turdetanians, on the contrary, draw from their 

 mines enormous profits, since the fourth of the earth which they ex- 

 tract from the copper mines is pure copper; and the silver mines fur- 

 nish private individuals in three days with a quantity of this metal 

 equivalent to a Euboic talent. As to tin, according to the account of 

 Posidonius, it is not found on the surface of the earth, as some his- 

 torians assert, but it is also extracted from mines. Mines of this metal 

 are found among the barbarous people who inhabit beyond the Lusi- 

 tanians and in the Cassiterrides Islands, and tin is also brought from 

 the British islands to Marseilles. Among the Artabri, in Gallacia, the 

 last people of Lusitania, on the north and west, there is earth covered 

 with a dust of silver, tin, and of the metal, known under the name of 

 white gold, on account of its alloy with silver. This dust is brought 

 down by the rivers, raked up by the women, and then washed by them 

 in sieves placed upon baskets. This is what Posidonius says as to 

 the mines of Iberia, 



Polybius, in speaking of those of silver which exist near New Car- 

 thage (Carthagena) says that they are 20 stades from the city, that 

 they are so great that they extend over a district of 400 stades in cir- 

 cumference, that they habitually employ 40,000 workmen, whose 

 labour brings to the Roman people 25,0U0 drachms per day (about 

 £350,000 per annum). I do not enter into the detail of all the other 

 operations, which would be too long, I confine myself to what Poly- 

 bius says as to the manner in which the silver is treated, which is con- 

 tained in the rivers and torrents. After having pounded and sifted it 

 over water, what remains is separated from the water and pounded 

 again ; after having been sifted again, it is pounded and sifted five 

 times in all. After this the pulverized matter is melted to separate 

 the lead contained in it, and the silver remains pure. These mines 

 of silver still exist, but there and elsewhere they belong to the state 

 no longer, but have been taken possession of by private individuals ; 

 those of gold on the contrary mostly belong to the state. Here as 

 well as at Castalon (Caslona) and in other places are mines of lead, 

 which contain silver, but in too small quantity to defray the expense 

 of separition. 



* B. 3, ch. 2. 



2 S 2 



