A Military Dictionary and Gazetteer / Comprising ancient and modern military technical terms, historical accounts of all North American Indians, as well as ancient warlike tribes; also notices of battles from the earliest period to the present time, with a concise explanation of terms used in heraldry and the offices thereof. The work also gives valuable geographical information. Compiled from the best authorities of all nations. With an appendix containing the Articles of war, etc.

by Thomas Wilhelm

The Lashings.—With respect to the lashings, the corresponding balks of adjacent bays lap each other by 6 feet, and are lashed together and to the gunwales at two points about 5 feet apart. Thus a strong splice is formed, making five continuous beams running the entire length of the bridge. The stability of the bridge is further increased by the manner of placing and securing the side-rails.

By Parts.—The abutment bay is formed as in the previous method. The parts are constructed at suitable points along the shore above the bridge, and for each is required the material for three bays. They are constructed as follows:

A ponton is moored bow and stern close to the shore, and five chess are temporarily laid from the bank to its interior gunwale, for the convenience of the pontoniers during the construction of the part.

The other two pontons are brought up in succession, and two bays are constructed in the ordinary manner, except that six chess are omitted from the roadway at both ends. Twenty-six chess and seven balks are loaded on the parts thus formed, which is then pushed off and conducted to the line of up-stream anchors, where it casts its anchor and drops down to its place in the bridge.

The first part is connected with the abutment bay by the pontoniers on shore, who construct one length of bridge flooring in the usual manner, to join the abutment ponton with the first ponton of the part.

The other parts are united as they come in position, by bays formed from the balks and chess with which they are loaded.

The down-stream anchors are cast by separate pontons provided for the purpose; and it may sometimes be necessary to cast the up-stream anchors in the same way, as the parts are not easily managed in a rapid current.

When the current is moderate, the parts may be constructed below as well as above the bridge.

By Rafts.—The abutment bay is laid in the same manner as in the last method, and the rafts differ from the parts only in having the roadway completed,—that is, the six chess at each end are not omitted. The rafts are not loaded with extra balks and chess, but are provided with two false balks, 6 feet 9 inches by 5 feet 5 inches, and with four rack-collars and wedges.

The rafts cast their up-stream anchors, and drop down to their places in the bridge. The outer pontons of the adjacent rafts are in contact, and are lashed together bow and stern by their mooring-posts. False balks are laid over the side-rails of the two rafts at their junction; and two rack-collars embrace each false balk, and the side-rails and balks under them. These collars are placed on each side, and 2 feet from, the junction of the side-rails. The wedges are driven between the false balks and the tops of the collars.