The Editor is always glad to receive for examination illustrated articles on subjects of timely interest. If the photographs are sharp, the articles short, and the facts authentic, the contributions will·receive special at tention. Accepted articles will be paid for at regular space rates. REINFORCEMENT OF THE BROOKLYN SUBWAY TUNNELS. In view of the popular distrust of the Subway tun: nels to Brooklyn, which was aroused at a certain period during their construction, a distrust which it took

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... ral weeks of successful operation to dissipate, we present some details of the method of strengthen' ing the tunnels during construction, which should be sufficient to satisfy the public once and for all not only that the tubes are "safe" but that they are stronger than as originally designed. The irregularJ.ty in the grades of a certain part of the. tunnel and the deformation of the cast-iron shell were caused by faulty control of the shield in the process of driving, couple' d with an undoubted weak ness of the cast-iron tube for the stresses it was �alled upon to sustain when it entered the loose ma terial below the river. The ,irregularities of gr!!de and weakness of the shell were, fortunately, capable of' correction; and the engineers of th!! Interborough Company spared neither' time no ! €xpense in repair ing the defects and putting this 'portion of the tubes in first-class condition. Toe pre�ent any tendel!cy of .the tubes to sag in the direction of their lengtlr-, 20inch steel-and-concrete piles were sunk, in pairs, at 30-foot intervals longitudinally of the tube, the piles bei�g carried down to solid rock or othllr firm ma terial. The grade was corrected by enlarging the. tun nel at the top or bottom, as might be required, until a perfectly true grade was established. An immense amount of work was done also to strengthen the tubes against distortion w.here they passed through the soft material. The concrete lining. was here made thick enough to extend 3 inches ' b�yond the flanges of the lining plates, and it was Specially increased in thick ness at the top of the tunnel and the sides, by making the outline flat instead of circular at these plac l( s. Inside of this €xtr , a concrete and around the top of the arch for a distance of 120 degrees circumferentially, there were imbedded three 114-inch round rods to each segmental ring of the tubes. Also, at the top of the tunnel there were imbedded sixteen longitudinal 1i4inch round rods connected at their ends by turn buckles. A 'similar number of circumferential rods were imbedded in' the bottom concrete of the tubes. On each side of the tubes, lapping the circumferential rods at the top and bottom, were placed two 1-inch square rods to each ring. It will be seen that the cast-iron lining of the tunnel is thus reinforced by what is practically a second shell of steel and con crete. So closely assembled are the steel bars and rods, that in some cases the concrete had to be put in place by hand, and extreme care was taken to secure a thorough bond between the materials. What ever grounds for anxiety may have once existed as to the stability of the tunnel have by these precautions been entirely removed. THE PANIC AND THE RAILROADS. Few pe'ople' who are not directly connected with the railroad interests of this country appreciate how seri ously they were affected by the panic at the close of last year. It came at a time when the devel opment of our railroad system, in the extent of its mileage, the magnitude of its rolling stock, and the enormous extent of its freight and passenger traffic, had reached a point that was undreamed of a few years ago, even by our most optimistic railroad men. In spite of the fact, as shown by the Interstate Com mf'rC'e Commission reports, that there were over 223,000 miles of line in the. country served by nearly 2,000,000 Scientific -AlDerican freight cars of 70,000,000 tons aggregate capacity, there was no little anxiety lest another car famine, similar to that of a few years before, should. occur. In the closing months of last year, however, 'the tide of new construction and increasing freight and pas senger traffic wa;:; suddenly halted and commenced to swiftly ebb-how swiftly is shown by the fact that at the opening of the present year there were over 300,-000 idle freight cars on the various railroads, while the returns made to the Interstate Commerce Commis sion reveal that, in the last three months of 1907, while the ratio of expenses to earnings had risen from 67 per cent to 76 per cent, there had been a decrease of earnings per mile of 31 per cent. According to an estimat� of Mr. S. Thompson, prepared for the Gen eral Managers' Association of Chicago, there were re cently about 340,000 railway employees out of work, whose idleness directly affected, probably, not less than 1,500,000 people. On the other hand, it is grati fying to learn from a statement issued by the Chief of the Bureau of Immigration that, as the result of se.'veral hundred thousand inquiries sent out by his office, to determine the present industrial conditions and the probability of demand for labor, he found in almost every industrial center and particularly in th� farming distriCts signs of a steagy return of activity and the probability during the next few months of a steadily increasing demand for labor.