Memoir of M. D^lubidsson de Voisins. 213 



was real economy in not having recourse to credit; the 

 impatience of enjoyment was subordinated to this economy ; 

 such was then the system. "We shall not stop to consider 

 the details of the constructions, which have been so well 

 given by M. D'Aubuisson himself in his " History of the 

 Fountains of Toulouse."* It may be enough for us to men- 

 tion, that having secured the adoption and execution of the 

 best hydraulic moving power, after having constantly assisted 

 the skilful mechanician who had undertaken it with his ad- 



* As few persons have the Histoire des Fontaines in their hands, it appears 

 proper that we should explain, in a few words, the hydraulic system of 

 Toulouse. 



The water of the Garonne furnishes at once the moving power and the 

 supply. The moving water is brought directly to the machines, placed at 

 45" from the river; the portion intended for distribution in the town is 

 alone filtered ; its quantity is 200 inches, and it can be increased to 250 inches, 

 or 100 litres, for each inhabitant, in twenty-four hours. It is filtered by being 

 washed across a bank of sand, which here forms the bank of the river, and 

 which has accumulated for nearly a century behind the bridge (no doubt in 

 consequence of the bridge being built). Galleries, with permeable walls, have 

 been made in this bank, at one metre below the etiagc, and with a develop- 

 ment of nearly 400 metres. They turn aside the limpid water into a reservoir, 

 whence they are raised in a chateau d'eau by machines to 20 metres above the 

 medium level of the waters of the river, and 6 metres above the culmi- 

 nating point of the town. These machines consist of two equipages with 

 independent pumps, formed by four pumps each, and each furnished with a 

 hydraulic wheel. These pumps, aspirantes, and foulantes, with a piston of 

 polished copper of the kind called phingers in England, passing across a fixed 

 box of leather ; they are united two by two at the extremity of the same 

 balance, in order to regulate the play and moving force. The two movei-s are 

 hydraulic wheels ; their diameter is 6"" 50, their breadth 1™ 50 ; the water is 

 let in l" 45 above their lowest point, and flows out by a subterranean canal, 

 which opens into a ravine at the distance of a quarter of a league. The total 

 fall of the water above the bottom of the wheels is 2" 20, and the quantity 

 distributed is about \\ cubic metre per second. The 200 inches of filtered 

 water are distributed in the town by ninety-one mouths, six of which are 

 monumental fountains, by means of a development of cast-iron pipes of ll'SOO'", 

 of which 1-300'" are double ; their diameter varies from 27 to 5 centimetres ; 

 without the doubling, the principal must be nearly a demi-metre. Their 

 thickness is between 15 and 10 millimetres. 



The total expense of a million is divided into nearly two equal parts ; 

 500,000 francs for the machines, the chateau d'eau, filterage, and canals, 

 and 500,000 francs for the distribution. 



