No man concerned in the larger management of railroads, who has not passed a morning in those London galleries, knows what it is to handle a great city's traffic. Perfect as it is in its way, however, it may well be questioned whether the block system as developed in England is likely to be generally adopted on American railroads. Upon one or two of them, and notably on the New Jersey Central and a division of the Pennsylvania, it has already been in use for a number of years. From an American point of view, however, it is open to a number of objections. That in itself it is very perfect and has been successfully elaborated so as to provide for almost every possible contingency is proved by the results daily accomplished by means of it.[13] The English lines are made to do an incredible amount of work with comparative few accidents. The block system is, however, none the less a very clumsy and complicated one, necessitating the constant employment of a large number of skilled operators. Here is the great defect in it from the American point of view. In this country labor is scarce and capital costly. The effort is always towards the perfecting of labor-saving machines. Hitherto the pressure of traffic on the lines has not been greater than could be fairly controlled by simpler appliances, and the expense of the English system is so heavy that its adoption, except partially, would not have been warranted. As Barry says in his treatise on the subject, "one can 'buy gold too dear'; for if every possible known precaution is to be taken, regardless of cost, it may not pay to work a railway at all." [13] An excellent popular description of this system will be found in Barry's _Railway Appliances, Chapter V_.