40 ANNUAL OF SCIENTIFIC DISCOVERY. 



The expense for repairs in the coal-burning engines is considerably 

 more than that for the wood-burning ones. This is caused by the rapid 

 burning out of the fire-boxes, grates, &c. When iron (whose sound- 

 ness is at present always uncertain) was used entirely in the fire-boxes, 

 the intense local heat very soon burned away the sheets near the 

 fire, and also the joinings of the sheets were affected. To obviate 

 this latter difficulty, larger sheets were used, but this only increased 

 the first trouble, and finally copper sheets directly about the fire were 

 resorted to. These, however, do not last long, and the expense for 

 repairs is large. The repairs have hitherto cost about $456 per 

 annum for each engine, but Mr. W. thinks this can be reduced to about 

 $380. If we calculate the price of fuel as stated above, the saving 

 in the coal engines would be as follows, allowing for 100 round trips 

 per annum : wood engine each trip costs $57.48 ; coal $25.85 ; 

 the excess of cost of wood per annum is $3,163; deducting extra re- 

 pairs, we have $2,787 as the actual saving in the Baltimore en- 

 gines. 



These engines being on a new plan, and burning a new fuel, labor 

 under great disadvantages, having no previous experience to guide 

 them ; but there can be little doubt that in a few years anthracite coal 

 will be used as fuel in locomotives on many of our railroads \vith a 

 saving over wood. 



TYLER'S SAFETY-SWITCH. 



THIS switch, the invention of Mr. P. B. Tyler, of Springfield, 

 Mass., possesses all the good qualities of the old gate-switch, and has 

 none of its imperfections. It seems fully to accomplish its object of 

 preventing the train from running off the track when the switch is set 

 wrong, either by design or accident. The single-rail or gate-switch is 

 established as the best and safest for the ordinary purpose of shifting 

 the cars from one track to another, but it is liable to the serious objec- 

 tion of leaving one track open or broken. Mr. Tyler's improvement re- 

 moves this evil, and, while it accomplishes this important office, leaves 

 the switch in its original simplicity of a plain, unbroken rail, connecting 

 one track with the other. An important feature in this safety-switch, 

 which distinguishes it from all others designed for the same pur- 

 pose, is, that the safeguard, or portion intended to protect the switch, 

 is always in position, and requires no action of the train to place 

 it right when it comes upon the open track; thereby avoiding all 

 reliance upon the movement of complicated machinery, which may 

 be displaced by ice, gravel, flaws in the material of which it is made, 

 or any of the known obstructions to such apparatus. It presents no 

 obstacle to ihe cow-catcher, snow-plough, or scraper, and requires no 

 change in the economy of the road more than the ordinary gate-switch. 

 The exact nature of the switch can probably be best understood by 

 giving a portion of the " claim" made in applying for a patent : 

 " The principle of this invention consists in constructing the moveable 

 parts of the switch with an additional branch, between which and the 

 true ^switch there is an inclined plane and a guard on the outside, so 



