lowed by a canal to Rio Tula.[1] On May 15, 1608, the first canal was completed, and on September 17th water passed through the tunnel in presence of the viceroy, amidst the rejoicings of the colonists who had reason to be proud of an engineering feat so rare at that time. It was not long, however, before the inefficiency of the work became apparent, the conduit being too small, on too high a level, and so poorly vaulted and faced as frequently to choke with its own debris. The efforts to remedy the latter defect proved of no avail,[2] and it was even proposed to construct another channel, for which, in 1611, Alonso de Arias made surveys. Martinez could not well be held to answer, for he had submitted other more thorough plans than the cheap and speedy one adopted.[3] Three years later the celebrated Dutch engineer. Boot, reported in favor of the ancient Aztec dike system for the capital, on the ground that the southern lakes were fully as dangerous as the northern. Martinez agreed to some of his views, but insisted that it was above all necessary to maintain the tunnel outlet.[4]
- ↑ Cepeda's figures, Rel., pti. 25, iii. 21, are 9,600 varas for the tunnel when first opened; afterward reduced by extending it into an open cut. Humboldt is not very exact in giving the tunnel a length of 6,600 mètres, a width of 3.5, and a height of 4.2.
- ↑ Unbaked mud bricks were soon rejected for wood facings, and these for masonry, but instead of an elliptic arch a mere vault was constructed, resting on an insecure foundation, so that the walls were undermined and fell in. The extent of the different facings some years later is given in Cepeda, Rel., iii. 21 et seq.
- ↑ Yet several writers seek to blame him, and assume that the rejected plans had been made by Sanchez. The canal project in 1604 was estimated to require a length of 6 to 9 leagues; now the length of a perfect drainage of the three lakes was placed at 70,000 varas, with a depth of 40. Cepeda, ubi sup.; Gemelli Careri, Giro, vi. 122. By this time the expenditure for the work according to official accounts amounted to 413,324 pesos out of 540,000 collected. In Mex., Rel. Estad., 2, the cost is placed at 1,140,000 pesos up to 1623. Instruc. Virreyes, 262. Gonzalez Dávila makes it 3,952,464 for the first few years, during which 128,630 laborers had been employed. Teatro Ecles., i. 2
- ↑ Martinez prevailed on the authorities to let him perfect the tunnel, but he failed to carry out the agreement, probably because his estimate of 100,000 pesos appeared on closer inspection to be too low. Boot's reports, and the discussion thereon, are given in Cepeda, Rel., pt. ii. 1-17. His views were strengthened by troubles from the southern lake water. Cavo, Tres Siglos, ii. 249. Boot appears to have been retained as active or consulting engineer from 1613 until 1640, with 1,200 ducats pay. Fonseca, Hist. Hacienda, v. 358-9.
