The Works Of Messrs. Schneider And Co.

V.—IRON MINES. The Mazenay and Change Mines.—These form two distinct concessions : (1) that of Mazenay, and (2) that of Change. As will be seen from Fig. 35, both concessions are very near together; and they are about 19 miles from Creusot, to which they are connected by the Paris, Lyons, and Mediterranean Railway, and by a line belongino' to Messrs. Schneider and Co. The ore actually worked is in a deposit 5 miles long and mile wide, the thickness varying from 20 in. to 8 ft. 6 in. The depth of the working shafts does not exceed 130 ft. The concession of Mazenay comprises 2,700 acres; that of Change 2,630 acres. The product of these mines is an oolitic calcareous ironstone. The beds are interrupted by dislocations, but the general direction has not been shifted. The St. Eugène pit at Mazenay has an annual output of 50,000 tons of ore ; that of St. Charles at Change, is 60,000 tons. At St. Charles, where the bed is of the greatest thick- ness, the analysis of dry ore shows a percentage of 30.90 of metallic iron, which is équivalent to 28.5 per cent, in the biast furnace. The varions iron ores mined in France contain widely variable percentages of phosphorus, and a remarkable feature of the Mazenay ore is that phosphorus is in constant proportion to the percentage of iron ; so that as samples become poorer in iron, and, therefore, richer in calcareous matter, the percentage of phosphorus decreases regularly, notwithstanding the increasing num- ber of fossil shells. The phosphorus, therefore, is not combinée! with the lime, but with the iron itself, forming a phospho-carbonate. A few years ago the ore was worked on the long-pitch system ; now the long-wall method is adopted, some of the faces of workings being 1,000 ft. in lengtli. This is found to be much more economical, especially where the bed is not very deep. On leaving the mine, the trucks are tipped direct into 10-ton wagons, and the ore is brought to the Creusot blast furnaces by the railway belonging to the company. The references on Fig. 35, a plan of the Mazenay and Change mines, are as follows : A. St. Charles shaft. B. St. François incline. C. St. Eugène shaft. D. Railway station. E. Incline. The Allevard Mines.—These consist of a group of seventeen concessions, which were acquired by Messrs. Schneider and Co. in 1874 from MM. Oharrière et Cie., and from the Marquis de Marcieu. They bave been worked at a great number of points since the beginning of the Century, but it is only of late years that their develop- ment lias been carried on in a satisfactory manner. They are connected with the Paris, Lyons, and Mediterranean Railway by a local line concecled to Messrs. Schneider and Co. in 1875, This line ends with four inclinée! planes. It leaves the concession at Taillai, at an elevation of 3,650 ft., and runs to the Cheylas station on the Paris, Lyons, and Mediterranean Railway at an altitude of 813 ft. The first three inclines are, together, 4,920 ft. long and the fourth is 1,640 ft. long. These planes account for a difference in level of 2,840 ft. between the mines and Cheylas station. The ore brought from Taillat by the first inclines is for the most part roasted, six furnaces being installée! for this purpose at Champ Sappey, at the foot of the incline. The concessions collectively cover 6,330 acres. The ofe is a carbonate of iron containecl in mimerous veins on the west side of the Belledone chain of mountains, and especially in the vicinity of Allevard. These veins are, as a rule, contained in crystalline slate, and in triassie quartz rock, which covers the slate. The furnaces in which the ore raised from these mines was melted at the beginning of the Century, have long since disappeared, and when Messrs. Schneider and Co. purcliased the concessions in 1874, they put clown entirely new plant. The average annual output is now 50,000 tons. The most important part of the mine is that known as Taillat, in which two principal veins are worked ; these are cut by D