Reports of the Massachusetts commissioners to the exposition at Vienna, 1873With special reports prepared for the Commission . trical, and might easily be over-come by mechanical means. It being suggested that the sig-nal-man might tie down the-arm of the semaphore with astring, Mr. Preece very aptly replied that he might alsoneglect his duty, disregard his signals, and swear that thesemaphore was down when it was really up. In the Tyer system a signal-man to change his own signalmust also change that of his neighbor, and this is probably asgood a control as putting it out of his power to inte
Reports of the Massachusetts commissioners to the exposition at Vienna, 1873With special reports prepared for the Commission . trical, and might easily be over-come by mechanical means. It being suggested that the sig-nal-man might tie down the-arm of the semaphore with astring, Mr. Preece very aptly replied that he might alsoneglect his duty, disregard his signals, and swear that thesemaphore was down when it was really up. In the Tyer system a signal-man to change his own signalmust also change that of his neighbor, and this is probably asgood a control as putting it out of his power to interfere elec-trically with his own indicator. The new system of Messrs. Siemens & Halske, exhibitedboth in the German and English departments at Vienna, goesa step farther towards the control of the signal-man thaneither the Preece or Tyer system. By the kindness of Dr. 480 EXPOSITION AT VIENNA. Werner Siemens,.of Berlin, I have been furnished with draw-ings of this apparatus which are here presented. A shows the external appearance of the apparatus at anintermediate station, the arms a, a^ of the semaphore being a, a^. worked by the cranks h, 5^. The arm a gives the signal forup, and the arm a} for down-trains. The crank c is used toturn a magneto-electric apparatus in the box, from which cur-rents are transmitted in one direction or another, accordinglyas the commutator knob or plunger d or d} is jrressed discs shown on the face are controlled by the current, and REPOET OF MR. ROBERT B. LINES. 481 show white or red as the line is clear or blocked on their re-spective sides. B shows the internal mechanism and connec- Plate XV. B ^ ^
Size: 1390px × 1798px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1870, bookpublisherbosto, bookyear1875
