first to disclose to the public a means of entirely consuming the fuel, and removing one of the strongest objections to them.

In most of the proceedings referred to, high pressure steam was used, the engine generally working under a pressure of 35lbs. ; but in some, low pressure steam was employed with equal advantages,—indeed there is every reason for believing that it will be greater.

Fortunately the process is of easy application. All that is required, in those cases where a boiler is in use, is merely to carry a small tube from any part of it, and which is made to terminate in the furnace, by a sort of fan, perforated with a number of small holes, so as to throw the steam in all directions down upon the flame; this can be done for a trifling expense, compared with the im

mense benefit derived. Should there not be a boiler attached to the furnace, a small one can be raised at little expense. Of course,

in stating the great saving effected, it must be kept in mind that part of the steam is consumed in accomplishing this, but it is small in comparison to the whole amount, not exceeding one-twelfth of the total quantity of steam raised from the boiler, and which must of course be deducted from the saving stated; but it is not always necessary to take the steam from the boiler. When high pressure engines are used, a pipe may be made to convey part of the waste steam into the furnace; and there are also many ways of generating steam, without any additional expenditure of fuel, which must occur to every engineer.Edinburgh Observer.

Upon the occasions of the previous meetings of the British Association we have given the proceedings of all the sections at considerable length; and many of our readers and correspondents have complained of our so doing—and perhaps justly-as filling up too great a proportion of our publication with matter not at all of a mechanical description. We shall avoid this fault in the present instance, and only give the proceedings of the Mechanical Section, and selections from that of the others bearing upon mechanics or manufactures. Altogether the meeting of the Association just past has been one of the most uninteresting -and in a mechanical point of view, the most meagre of the eight periodical assemblages that have taken place. The Reports that have been published are also very unsatisfactory and too general. We shall be most happy to receive any of the papers read at the Mechanical Section, of which mere mention is made, or only a scantling given in the Reports, for publication in our Journal.

"A Statistical View of the Recent Progress, and Present Amount of Mining Industry in France," by Mr. G. R. Porter.

Mr. Porter began by a general reference to the importance of the subject, and observed, that it is surprising that, among a people so proverbially practical as we are, such researches should be so little the subjects of inquiry as they hitherto have been : even the amount of one of the most important of our mineral products is so much left to conjecture, that the produce of our

to

coal-mines at the present day is variously estimated by men conversant with the subject, at from 15,000,000 to 30,000,000 of tons per annum. In France, however, a law was passed, in April 1833, which gave authority to collect statistical details of the mining industry of France, and intrusted the execution of the duties subjoined the a public department, known as 'Direction Générale des Ponts et Chaussées et des Mines,' and placed under the ultimate controul of the Minister of Commerce and Public Works. Attached to this department is a staff of well-instructed, able engineers, who make a personal inspection of every establishment connected with mining operations; and a report is carefully drawn up from materials supplied by these officers, and presented every year to the Minister of Public Works. These reports present a most elaborate view of every branch of mineral industry in each department of the kingdom; and from tables, the result of which will be given hereafter, it will be seen at what a rapid rate of increase the mineral resources of France have of late years been developed-a rate which Mr. Porter thought might reasonably suggest the probability of its being in some part owing to the public attention having been drawn to the subject, and still more to suggestions offered to the proprietors of works by accomplished engineers at times when the works have been inspected. The increase in the value of coal, iron, lead, antimony, copper, manganese, alum, and sulphate of iron, since the system of inspection was begun, has been from 105,750,995 francs, (4,230,0397.), in 1832, to 154,228,455 fr. (6,169,1387.), in 1836, or 45 per cent., as under :

Iron. At the present time France occupies the second rank among nations as regards the production of iron, England being still immeasurably in advance of France, in which country the extension of this branch of industry is far less than has been effected of late years with us. There are at this time in France twelve distinct localities or districts, in which the making of iron is prosecuted, which are thus distinguished in the official reports :-1. Group of the Northeast; 2. of the North-west; 3. of the Vosges; 4. of the Jura: 5. of Champagne and Burgundy; 6. of the Centre; 7. of the Indre and La Vendée; 8. of the coal-fields of the South; 9. of Perigord; 10. of the Alps; 11. of the Landes; 12. of the Pyrenees.

The actual and relative importance of these groups may be seen from the following particulars, given in the Report presented in the present year, and having reference to the working of 1836.

The figures given in the foregoing table do not present in all their importance the extent of this branch of industry in France. The number of workmen employed for the production of pig-irou (fonte), malleable iron (gros fer), and steel, which alone are there included, does not much exceed onethird of the number engaged in all the various processes of the iron manufacture; and the total value of the material produced, instead of being, as in the above statement, 3,585,7397., amounted in 1836, according to the returns of the inspectors, to 4,975,4241. The following abstract contains all that it appears desirable to offer on this occasion, and presents under five principal divisions the total number of workmen engaged in the manufacture, with the value created by them in each of those divisions :—

The increased proportion of wood, observable in the working of 1836, is caused by the substitution in part, in some works, of wood dried by heat or partially carbonized. By the introduction of a proportion of dry wood in place of charcoal, a diminution in the cost of fuel has been attained, but against this advantage must be placed the smaller produce obtained from the furnace in a given time, as well as a diminution of metal from a given quantity of ore.Where wood charcoal alone is used for smelting, it requires eighteen metrical quintals for the production of thirteen metrical quintals of iron. Where coke and coal are used in the proportion of ten of the former to nine of the latter, it requires about three quintals of fuel to produce one quintal of

iron.

In some cases, coke is used with charcoal in the proportion of one quintal of coke to two quintals of charcoal, and the produce has been eight quintals of iron for ten quintals of fuel. In the first case (where wood charcoal is used), the cost of

The mixture of coke and charcoal would, upon the whole, appear to be the most profitable in its result. Deducting from the value of the metal the sum expended for fuel, there would remain, when charcoal alone is used, 41. 9s. 10d. per ton; when coal and coke are used, 27. 14s. 2 d. per ton; and when coke and charcoal are used, 51. 3s. 3d. per ton. These calculations are of course wholly inapplicable to the circumstances in which the manufacture is placed' in this country, from the actual and relative cheapness of our mineral fuel. The use of the hot blast has been adopted in several of the furnaces in France. At first it was found that the iron thus obtained was not so well adapted for making bar iron as that for the smelting of which cold air had been used; but some modifications, which are not particularized in the Reports, have been introduced into the process, and this advantage has been remedied. No account is given of the quantity of iron made in France earlier than 1824; but from that year the account is regularly stated in the Reports from which the following abstract has been computed :

The production in France of metals, other than iron, is of little or no commercial importance at the present time. The whole value created in the articles of lead and silver, antimony, copper, and manganese, amounted in 1836 to less than 60,0007., and gave employment to only 1760 workmen. In noticing this fact, the inspectors encourage the hope that some considerable addition may shortly be made to the produce of mining industry applied to the articles just enumerated; they do not, however, explain the grounds upon which this hope should be entertained, further than by noticing the existence in the country of several promising fields for that industry hitherto allowed to remain unproductive, and by stating that they are occupied in collecting information which may serve to facilitate the future attempts of persons desirous of embarking their energies and their capital in this direction.

Lead and Silver.-There are eleven lead mines in operation in France, situated as under :

Copper. The produce of copper mines in France, five in number, is inconsiderable: three of these mines are in the department of Hautes Alpes, and two are in the department of the Rhone. The quantity of metallic copper which they yielded in 1836 was only 102 tons, and its value 7,8771. The yearly consumption of foreign copper, principally the produce of Russia and of England, during the five years from 1832 to 1836, has averaged 6,235 tons. Manganese. The manganese mines are situated as follows:

The engineers to whom the task of inspecting the mining establishments of France is intrusted, have not confined their inquiries to the objects which have been noticed in this paper: they have included in their Annual Reports the statistics of various branches of industry in which mineral substances are produced or employed; such as bituminous minerals-alum-sulphate of iron-and salt; the produce of quarriesof glass-houses-of porcelain and pottery manufactories of copper and zinc worksand of chemical processes. By this means, it is shown that the number of workmen who, in 1836, depended for subsistence upon mining operations and their consequences, amounted to 273,364; while the total value created by their joint labour amounted to 377,684,791 fr., or 15,107,3927. viz :