Mr. Garneit referred the Society for a more full description of 

 the Tide Trunk than he gave, and for a Cut of it, to the 2d 

 Vol. of Ski7iner^s Americayi Farmer : — the following Explana- 

 tion is therefore taken from that Work. 



EXPLANATION OF THE PLATE. 



" Fig. 1. — A B represents the trunk, open at the end A, and 

 closed at B, with an aperture on the top at F, near the end B ; 

 the frame C D is attached to the trunk, and is intended to hold 

 the iron rod E, in a perpendicular position, which is attached at 

 the lower end to the valve, and holds it in its place. This valve, 

 floating with the flowing of the tide into the trunk at A, rises 

 and closes the aperture F perfectly, so soon as the water rises 

 to the top of the trunk. 



Fig. 2. represents this perpendicular iron rod G, passing 

 through the external frame, and the aperture at I, and attached 

 to the valve H by a hook. This iron rod must be allowed to 

 play with perfect ease through the frame, and be so light as not 

 to prevent the valve from floating, and if there be any apprehen- 

 sion of its sinking the valve, the under surface of the valve may 

 be coated with cork to make it sufficiently buoyant to rise with 

 the rod. 



Fig. 3. represents an interior view of the end of i\\t trunk. — 



1. The aperture at the top. 4. The end next to the marsh closed: 



2. The valve lying at the bottom : 3. Two perpendicular rods 

 passing through the trunk, and intended to confine the valve in its 

 place, instead of the rod described in fig. 2. which method of retain- 

 ing the valve in its place, has its advantages, and is by some pre- 

 ferred to the rod. The upper surface of the valve must be smooth, 

 and made to fit closely the under surface of the top of the trunk 

 round the aperture, in whatever way it may float up to it. When 

 the tide recedes, the valve falls to the bottom, opens the aper- 

 ture at F, fig. 1. and the water from the marsh pours into the 

 trunk, and runs off into the river at A, fig. 1. 



This trunk has been found, on actual experiment to exclude 

 every drop of water from the flood tide ; but as the water pro- 

 posed to be drained off, must flow over the top of the trunk, and 



