INLAND NAVIGATION.

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a. The river. b. The canal. c. Towing-path. d. Warehouses,c. A bed (technically Tkpunn) of clay, to prevent the water weepingthrough the arches, f. The canal continued by embankment.

It may not be amiss to describe here the process of making puddle, anarticle of great use in completing canals where the foil is leaky, or unfa-vourable for holding the water. Before the practice of using it wasknown, many works otherwise good have failed.

The invention was, I think, first discovered and practised by Mr.Brindley, and is as follows i

Take a quantity of earth sifted very sine, and beat it up well withwater, like thin mortar ; then spread it on the places to be secured ; letit be quite dry, and repeat the fame several times ; which will make awall, or lining, through which the water will not penetrate. In thismanner the tanners line their pits, and make them hold water.

In the line of a canal many Bridges are generally neceflary. Wegive a design for one suitable for a public road, and constructed on themost economical principles..

slate III. Elevation , &c. of a Bridge.

a. The canal. b. Plan of the foundation, c. Towing-path underthe bridge, d. Plan of the superstructure.

Also, a canal in its course often divides lands with which some com-munication is necessary for the purposes of husbandry. The easiest me-thod is shewn on plate IV. This is called an accommodation bridge. Ithangs by large hooks and eyes, or hinges, and is worked up and downwith ease by means of the balance poles. This view also shews a tow-ing-path gate, which is used for dividing grounds, and is hung so as al-ways to fall to.

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