Abstract: Method of constructing a tunnel under an existing structure, such as railroad tracks, without disruption of the existing structure, i.e. without interrupting railroad service on the tracks and without requiring construction of expensive track run arounds. The method comprises the steps of boring or drilling a plurality of pipes in side-by-side relationship generally horizontally beneath the railroad right-of-way; if need be, reinforcing the pipes to assist in carrying incremental components of the loading on the tracks; incrementally excavating a small segment of the tunnel immediately beneath said pipes and placing tunnel forming members in the excavated segment in supporting relationship with the pipes; and repeating the last two steps until the tunnel, complete with tunnel forming-pipe supporting members, extends beneath the railroad tracks and right-of-way.

Abstract: A standard breath alcohol test medium comprises a canister containing a charge of nitrogen and vaporized alcohol having a predetermined amount of alcohol per unit of volume therein, and means on the canister accommodating discharge of the nitrogen and alcohol mixture therefrom, preferably by pressure discharge or hypodermic extraction through a self-sealing septum in the wall of the canister. A method for filling the containers with a predetermined amount of alcohol vapor is also disclosed.

Abstract: A pair of molded plastic covers are connected along one side by a hinge, and a plurality of cards are removably mounted in an overlapping relationship on the interior surface of each of said covers. The hinge comprises a post secured in a spaced relationship from an edge of each of the covers, and a double barrel member journalled on and hingedly connecting the respective posts. The surfaces on which the cards are mounted are molded with a concave configuration to allow the overlapping cards to lie flat. The cards are mounted on wire hangers which project into spaced grooves on the mounting surface.