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in an alarming proportion, when the works have reached a perpendicular depth of 500 metres*. The piercing and walling of the three old draught-pits cost the count de Valenciana nearly six millions of francs, viz.



The square pit of San Antonio or tiro viejo, 227 metres of perpendicular depth, and four baritels a chevaux

The square pit of Santo Christo de Burgos 150 metres in depth and two baritels a chevaux

The 'hexagonal pit of Nuestra Señora de Guadalupe (tiro nuevo) 345 metres in perpendicular depth and six baritels a chevaux



Expence of the three pits.


Within these twelve years they have begun to dig in the solid rock, in the roof of the vein a new draught-pit (tiro general) which will have the enormous perpendicular depth of 514 metres f, terminating at the actual

* 1640 feet. Trans. + 1685 feet. Trans.

I reduce the varas mexicanas on the principle that a vara is equal to OT 839 or + toise = 2.332 varas mexicanasa

bottom of the mine or at the planes of San Bernardo. . This pit which will be in the centre of the works, will considerably diminish the number of the 980 miners (tenáteros) employed as beasts of burden to carry the minerals to the upper places of assemblage. The tiro general which will cost more than a million of piastres * is octagonal and contains 26". 8 of circumference t. Its walling is most beautiful. It is believed that they will reach the vein in 1815, although in the month of September 1803 the depth was not yet more than 184 metres [. The piercing of this pit is one of the greatest and boldest undertakings to be found in the history of mines. It may be questioned, however, whether for the sake of diminishing the expences of carriage and draught, it was expedient to recur to a remedy which is at once slow, expensive, and uncertain.

(See Vol. ii. p. 165). In that country they consider the mines of Valenciana the deepest ever dug by man. At the period when I measured the planes of San Bernardo, the mine of Berchert Glück, at Freiberg in Saxony had reached 447 metres of perpendicular depth (1465 feet Trans.) It is believed that in the sixteenth century the works of the Saxon mines on the vein Alter Thurmhof went as far as 545 feet in depth (1787 feet. Trans.). Author.

* £218,767 Sterling.
+ 87 feet. Trans.
$ 603 feet. Trans.

The expences of working the mine of Va. lenciana have been on an average annually :

Piastres From 1787 to 1791

410,000* From 1794 to 1802

890,000+ Although the expences

are doubled, the profits of the share-holders have remained nearly the same. The following table contains an exact states of the mine for the last nine years.

* £89,694 Sterling. Trans. + £194,708 Sterling.

# Estadlo que manifiesta el valor de los frutos que ha producido la mina de Valenciana, costa de sus memorias y hiquido producto, a favor de sus duenos ; lo presentò Dor Joseph Antonio del Maso al Excellentissimo Señor Virey de Nueva Espana Don Joseph de Yturigarray, el 3 de Julia 1803. (M.S)

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The result of this table is, that the net profit of the share-holders, has been latterly at an average of 640,000 piastres per annum.* In 1802 circumstances were extremely unfavourable. The greater part of the minerals were very poor, and their extraction attended with great expence; and besides this, the produce was sold at very low prices, because the want of mercury impeded the amalgamation, and all the mines were incumbered with minerals. The year 1803 promised greater advantages to the proprietors, and they reckoned on a nett profit of more than half a million of piastrest. I saw them sell weekly at Valenciana, silver minerals to the amount of more than 27,000 piastres : The expences amounted to 17,000. At Rayas, the profit of the proprietor was greater, though the produce was less; for this mine furnished more than 15,000 piastres of minerals weekly, while the expence of working only amounted to 4000 piastres. This was the effect of the richness of the minerals, their concentration in the vein, the inconsiderable depth of the mine, and consequently a less expensive draught.

# Above 3,360,000 livres tournois ($140,011 sterling. Trans.) The profit distributed annually among the share." holders of the district of Freiberg, only amounts to 250,000 livres ( <10,417 Sterling. Trans.)

+ €109,383 Sterling. Trans.

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