NOTES ON MAJOR COAXES* DISCOVERY. 85 



much larger the consumption of water was in Roman times than 

 it is now, and how necessary an abundant supply of water was to 

 those who accepted Roman civilisation and adopted Roman 

 habits, and it supplies the motive for the construction of an 

 aqueduct at Dorchester. That Roman wells have been found 

 at Dorchester need not cause surprise ; there are wells in 

 Pompeii, though the wells there had to be sunk through 100 feet 

 of solid rock, yet Pompeii was abundantly supplied by aqueducts 

 with water from a distance, for there is none suitable near. 

 From the fact that the River Frome flowed at that time so far 

 from the town, and that it would have been necessary to cross a 

 marsh or stagnant water to reach it, as well as from the known 

 preference of the Romans for spring or rain water from a pure 

 surface,* it seems improbable that any quantity of water for 

 domestic and public uses was ever obtained from that source, so 

 that the need of an aqueduct must have made itself felt before, 

 or as soon as the population of the town became numerous 

 enough to justify the construction of so important a work ; and 

 the ingenious way in which the Romans supplied that want, the 

 knowledge of engineering and levelling shown in its construc- 

 tion, should excite the admiration of all, especially of those who 

 believe that the science of engineering is of comparatively 

 modern date. 



Our knowledge of the manner in which the Romans built 

 their aqueducts is obtained mainly, I suppose, from Vitruvius. 

 According to him, the Romans conveyed water by three ways 

 either by water channels, or by means of leaden pipes, or 

 through earthenware tubes. Vitruvius preferred earthenware to 

 leaden tubes, because the water conveyed through the former 

 was more wholesome than that which passed through the latter, 

 which might be contaminated with white lead, and because the 

 first cost would be less, and an earthenware pipe, if broken, 

 could be replaced by anyone. These are the reasons he gives 

 for his preference.! The earthen pipe was made with a collar 



* Vit. 1.8. c.2. Vit. 1.8. c.7. t Vit. 1.8, c.7, 



