In Belgium, Mr. Behr, who throughout his labours there received the personal encouragement and patronage of King Leopold II., successfully built an experimental high-speed mono-rail line at Tervueren in the neighbourhood of Brussels, as an annexe to the Exhibition of 1897. To find suitable ground was the great difficulty. The line had to cross ten public roads, and in the absence of compulsory powers, leases for the land had to be arranged with grasping occupiers and owners. The soil was bad, big cuttings and embankment were unavoidable, and finally the line consisted of nothing but steep, up-and-down gradients. In fact, all the conditions were most unfavourable, notwithstanding which, the result of the experiment was conclusive in showing that with the mono-rail and perfected electrical traction, very high speed, double that of existing passenger express trains, could be attained with absolute safety, a principle which Mr. Behr had for a long time past been particularly impressed with, but which he maintains is not possible on the ordinary two-rail track, even with electricity as a motive power. In November, 1901, Mr. Behr went to Berlin, and investigated the experiments carried out during forty days by a number of engineering experts on a military track laid down between the German capital and Zossen. It was hoped that a speed of 160 miles an hour would be attained and maintained, and, as a matter of fact, starting from a low speed, the train gradually reached that of 87 miles; then, for a moment only, 95 miles; and for an instant of time, 100 miles per hour; but it was at once discernible that the ordinary two-rail permanent way, though straight, could not bear the terrific strain imposed upon it; the rails bent at many places, while the hundred-miles-an-hour rate had so destructive an effect as to render impracticable any attempt to create a higher record. The air resistance was found to be considerable. With a square-fronted instead of a pointed coach, it was appreciable, and the suction behind the train resembled the pressure of the water at the stern of a mail steamer, and was calculated to equal two-thirds of the “bow” resistance. These experiments went to prove that for excessive velocity an ordinary railway was absolutely unsafe. A year before this, a steam locomotive train had been tried in America by the Baltimore and Ohio Railway Company, on the Adams principle of reducing the atmospheric resistance to a minimum. It consisted of six cars, a tender, and an engine of fifty-seven tons. The entire train was sheathed down to within eight inches of the track. There were no projections, and all the windows were flush; the cars were coupled close together, and the rear one was run off to a point, the train resembling one long sinuous and flexible carriage.