It appears, from the table, that a large pon-toon will be sunk about 5-£- inches, by 2497 lbs,its own weight, together with that of its apper-tenances.

A small pontoon will be sunk about 6 inchesby 1729 lbs. its weight, and that of its apparatus.

In forming a bridge, the pontoons are gene-rally placed at the distance of their breadthasunder, when there are a sufficient number toadmit of it. The intervals should never be lessthan this: but they may be increased, in case ofa deficiency of pontoons, extending, in propor-tion, the order of march of troops in crossing.

The greatest weight of infantry that can beput in march across a pontoon bridge, is whenmoving under a front of four men, files close;when, allowing the distance of five feet betweenpontoons, there will be about 20 men on each,and its interval.

Immersion of a large Pontoon with the Weightof Twenty Men.

lbs.

The weight of 20 men, each taken at 180lbs. is ..... 3600

Add the weight of the pontoon and its ap-pertenances ..... 2497

Total 6097

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