638 KANSAS CITY REVIEW OF SCIENCE. 
of an explosive ; next to remove this apparatus so as to leave the tunnel unob- 
structed ; next to charge and fire the blast ; then to load the excavated material 
upon cars that are run in for the purpose, and after loading, by hand run them 
out and dump, after which the drilUng apparatus is taken back into the tunne 1 
and the whole operation repeated. By this method of operation a large portion 
of the time has been required for the removal of the excavated material, and but 
a fraction of the time has been available for such work as required skilled labor, 
and the construction of a tunnel having any considerable length, has from such 
cause required so much time as to prevent many similar enterprises from 
being carried out. To obviate these objections is the design of the apparatus 
now in hand, which consists, principally, in a car having an open front end 
and adapted to receive the material as dislodged by the blast and provided 
with a movable top and sides which may be arranged with a chain and bar 
combination, to practically close the tunnel and cause the flying debris to 
fall into the said car. There can also be an adjustable drop apron attached to 
the extreme front end of the car bottom to prevent any of the material from being 
blown under the car. The platform, or body of the car, is supported upon four 
or more wheels, that preferably are of much less diameter than those usually 
employed, bringing the car as near the rails as possible. Secured to, and extend- 
ing upward from one end of the body, is an end piece, which has substantially 
the intended height of the box, while from each side edge of the said body a 
side piece extends upward to about one half the height of the end piece, and 
has, hinged to its upper edge a similar piece, that, when placed vertically, carries 
the height of each side up to that of the end piece. Hinged at one end to or 
upon the upper edge of the end piece, is a top or cover which has such dimen- 
sions as to enable it to close the entire upper side of the car-box when the hinged 
side pieces are turned inward to a vertical position. This cover is adapted to be 
raised upward to reach the roof of the tunnel and is thus raised when desired by 
the following described means, viz : Hinged at one end to or upon the rear end 
of the cover, is a bar, that at its outer end is provided with a pulley around 
which passes a rope that has one end connected to a windlass journaled upon 
the rear end of the car, and the other to the upper side at or near the front end 
of the cover. The said bar when not in use is turned rearward and downward, 
where it rests entirely out of the way, but when it is desired to raise the cover 
the bar is turned upward and forward until it reaches a vertical position, and 
when its further movement in such direction is arrested and by the turning of 
the windlass, the rope drawing over the pulley will cause the front end of the 
cover to be elevated. The upper face of the body, the inner faces of the end 
pieces, the sides, and the lower face of the cover, are heavily plated with metal, 
preferably with *'T" rails in order that they may be able to withstand the impact 
of flying rock, and in order that the points between the side pieces may be pro- 
tected from injury, and at the same time be made sufficiently close to prevent 
the passage of stones, the continuous edges are bevelled outward and their hinges 
are placed upon a Hne with the inner faces of the said parts. The box thus con- 
