Notices respecting Neic Books, 311 



width, says our author, to be given to platforms of terminal sta- 

 tions admits of much difference of opinion. At Cannon-Street, 

 where land was extremely expensive, and every dimension was 

 carefully apportioned, " the platform area is probably mini- 

 mized; but the station accommodates efficiently a very large mixed 

 traffic of long- and short- journey trains, amounting at times to as 

 many as 400 trains in and 400 trains out in a working day." To 

 accommodate this enormous amount of traffic, there are an eastern 

 and a western platform, each being 13J ft. wide, and having a line 

 of rails on both sides, the former being 522 ft., the latter 486 ft. 

 long. These are for local traffic; the general departure platform 

 for main-line traffic has a line of rails on each side, and is 19 ft. 

 wide and 6Q5 ft. long ; the general arrival platform is 721 ft. long, 

 has a cab-road through the middle, and a line of rails on both sides 

 —as appears from the plan (p. 194) ; but possibly only one side is 

 commonly used, as our author describes it as being 12 ft. wide 

 opposite the cab-road, 30 ft. wide beyond it, and as having a line 

 of rails on one side only. 



The chapters on signals and on the block system are those to 

 which the general reader will be likely to turn with most interest ; 

 these bear most immediately on the question will the journey be 

 safely made or not ? On this head Mr. Barry has good tidings 

 for him. Like a practical man, it is true, our author scouts the 

 notion of absolute safety for the passenger ; that would be incon- 

 sistent with the interests of the company : " if every possible 

 known precaution is to be taken, regardless of cost, it may not pay 

 to work a railway at all" (p. 179). But short of this a great deal 

 can be done. A nervous traveller, who has noticed the rails and 

 points near Cannon-Street, will take coinage when he reads the 

 following statement. There are, it is true, seventy point and signal 

 levers capable of being combined in many millions of different 

 ways, all dangerous except SOS combinations which are safe ; all 

 the levers, however, are brought into a single house and locked 

 together in such a manner that no combination but one of the 808 

 can possibly be made. " If a man were to go blindfold into a sig- 

 nal-box with an interlocking apparatus, he might, so far as accord- 

 ance between points and signals is concerned, be allowed with 

 safety to pull over any lever at random. He might doubtless delay 

 the traffic, because he might not know which signal to lower for a 

 particular train, but he could not lower such a signal, or produce 

 such a combination of position of points and signals, as would, if 

 the signals were obeyed, produce a collision. The results of the 

 interlocking principle may be illustrated by the example of a piano 

 or organ, constructed iu such a way that no notes could be played 

 on it which are not in harmony with each other " (p. 113). 



Mr. Barry gives a lucid account of the Block System — a name 

 which the system will doubtless retain, though it is not very ap- 

 propriate and its origin is doubtful, — and of the modifications by 

 which its signals are adapted to different circumstances. Thus at 

 a roadside station bell- signals may be sufficient ; but these would 

 not do at a terminus where, as at Camion-Street, a large number 



