538 



FRENCH EXHIBITION. 



hospital patients in the field of battle. France, 

 Prussia, and the United States of America 

 have all three contributed to form a complete 

 collection of such military necessaries. 



In the Ihiited States sanitary collection, 

 by Dr. Thomas "W. Evans, are four different 

 kinds of ambulance, a model of a railway am- 

 bulance, or hospital-car, being a foe-simile of 

 the hospital-cars employed during the war by 

 the United States Sanitary Commission on the 

 railways. This model, constructed on a scale 

 of one-fourth, shows in detail every thing 

 couches, dispensary^ wine-closet, water-closet, 

 systems of ventilating, heating, etc. employed 

 in the construction and equipment of the Sani- 

 tary Commission cars ; while at the same time 

 externally it perfectly represents the construc- 

 tion of an ordinary American 'passenger-car. 

 To it is attached a patent safety-brake, as well 

 as a set of self-acting ventilators. 



One or two sets of hand-litters, and a horse 

 litter, together with various ambulances of sup- 

 ply, including medicine-wagons, an ambulance 

 kitchen, medicine-panniers, hospital knapsacks, 

 etc., complete one portion of the collection, 

 another consists of models and plans of per- 

 manent brick-built hospitals; a model of a 

 Pavilion of the United States General Hospital 

 at Chestnut Hill, showing the exterior and in- 

 terior construction of a ward pavilion, the 

 mode of ventilation and heating, the latrines, 

 bath-rooms, and offices, together with the 

 arrangement of beds, furniture, etc. A fac- 

 simile of the log-houses employed in the con- 

 struction of the United States General Hos- 

 pital at City Point, two field-hospital tents, 

 the one square and the other called "the um- 

 brella tent," and specimens of hospital furni- 

 ture, together with surgical instruments and 

 apparatus, sanitary supplies of clothing and 

 food, and various publications relating to the 

 same subject. 



APPARATUS AND PEOCESSES OF THE ART OF MINING AND 

 OF METALLURGY. 



Models and Plans of Mining Localities. 

 Some of the most remarkable works of this 

 class are those which illustrate the complicated 

 structure of that important coal-field which ex- 

 tends from the Belgian frontier through the 

 Department du Nord and far into the Pas de 

 Calais. The map of the Pas de Calais (on a 

 scale 1 to 10,000) shows the energy and sys- 

 tem with which, by means of an elaborate 

 series of borings accurately recorded, the de- 

 velopment of a valuable new coal-field has 

 been accomplished within a very few years. In 

 1846 a boring for water at Oignies, not far from 

 Douai, gave evidence of the continuation of the 

 coal measures beneath the cretaceous strata in 

 this direction. The borings of the Escarpelle 

 Company proved that the coal formation was 

 sharply deflected northwestward from its old 

 direction at Valenciennes; and hence arose, 

 between 1850 and 1864, the establishment of 

 19 new concessions. Some 40 pits have al- 

 ready been sunk, having, on an average, 100 to 



150 metres of overlying formations to pierce, 

 and down to depths of from 180 to 300 metres 

 for their workings. The amount annually pro- 

 duced from this new and unseen district of coal 

 has increased steadily from less than 5,000 tons 

 in 1851 to upward of 1,600,000 tons in 1866. 



Plans of a most accurate character, on the 

 scale of 1 to 5,000, have been prepared from 

 elaborate surveys to represent the conditions of 

 the still more valuable but old-established coal- 

 field of the Loire; and a beautiful model has 

 been constructed to exhibit the singular curves 

 of the great seam of Rive-de-Gier in the same 

 district. This so-called grande masse, varying 

 from 26 feet to above 50 feet in thickness, has 

 been so far explored as to enable all its folds 

 and faults and other accidents to be shown 

 with great minuteness, the small portions which 

 are still uncertain being left blank. 



Another representation of the surprising prog- 

 ress made by France within a single generation 

 is exhibited by the mining company of the Grand 

 Combe, most important to the south of France, 

 and already third on the list of the French coal- 

 districts for its amount of production. 



The excellent plans and sections in which the 

 Prussians have recorded their important ex- 

 plorations of Westphalia and Silesia come rather 

 under the head of geological maps, and were 

 reported on at the Exhibition of 1862. 



Working of Mines. The coal-fields of Cen- 

 tral and Southern France, although individually 

 of small extent, are remarkable for the occur- 

 rence of seams of extraordinary thickness. 

 The tolerably regular beds of coal at Blanzy 

 and Montceau run to 50 feet and even 60 feet 

 thick; that of Creusot, where it is raised up 

 into a vertical position, varies from a few feet 

 to 50 feet, 80 feet, and as much as 130 feet, 

 measured right across ; and the great seam of 

 Decazeville (Aveyron) often extends to 100 feet 

 in thickness. Their very magnitude, to say 

 nothing of their often distorted position, entails 

 on the workers a variety of difficulties, which 

 it has taken a great number of years success- 

 fully to surmount. One method after another 

 has been tried, to guard against crush and 

 creep, alike destructive to the getting of coal 

 of fair size, and dangerous to the lives and limbs 

 of the workmen. But the only full and satis- 

 factory method is that of systematic "packing" 

 of all excavated places, except the needful 

 roads with rubbish (remblais) carried down 

 from the surface for that purpose. The large 

 block model of the Creusot collieries shows very 

 fully the curiously irregular position of one of 

 these seams; and the model in the midst of 

 the iron productions of Commentry illustrates 

 the means of working away the successive 

 horizontal ranges of the thick coal-bed of that 

 locality, by the aid of a close packing. The 

 amount of coal raised in France has risen from 

 1,800,000 tons in 1830, to close upon 12,000,- 

 000 tons in 1865. And the importations of 

 1865, chiefly from Belgium, amounted iu coal 

 and coke to about 7,100,000 tons. 



