PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 67T 



1st. It cultivates the ground after spring or fall plowing, 



2d. It sows the seed, either throwing it under the cultiva- 

 tor teeth, and plowing it in, for peas, &c., or by simply turning a 

 guide-board it passes directly under the drag, and sows it at 

 equal depths near the surface, 



3d, It covers the seed by a fine-toothed drag, which does not 

 allow any lump to pass larger than one inch square. 



4th. It sows the clover and timothy seed in separate compart- 

 ments, 



5th. It rolls the ground, preparing it for the mower. 



6th. It sows the plaster, guano, phosphates, &c., in the most 

 even manner, without the possibility of choking or any annoy- 

 ance from their dust. 



7th. It clears itself from all obstructions.. 



8th. The team always being in advance, the ground never is 

 poached with the horses feet, 



9th, The seeds and plaster can be sown in a gale of wind, 



10th, The farmer has no labor to perform except that of driv- 

 ing and filling up the seed boxes, 



11th, It is easy of draft ; by dynamometer test it requires but 

 50 pounds to draw it on the floor ^ 120 pounds on the road, and 

 on average soils less than 500 pounds when in full work, 



12th. By the turn of a thumb-screw the quantity of any kind 

 of seed can be regulated at pleasure, seeding from one peck to 

 five bushels to the acre. 



13th, By a peculiar construction of the cultivator and drag- 

 teeth, an inverted sod can be cultivated, without disturbing it, 

 which, when pressed under, is estimated to be equal to twelve 

 tons of manure to the acre, 



14th. The farmer can sow until the storm actually comes on. 



15th, The combined weight of the whole machine is only suffi- 

 cient to crush the clods that it may pass over, 



PROJECTILES, 



Mr. Clark submitted a model (in wood,) of a projectile in the 

 shape of a cylinder, surrounded by a packing case of soft mate- 

 rial, intended to expand so as to stop the cartridge, and to leave 

 the shot free as it comes out of the gun. The expansion is caused 

 by a tendency of the shot to force itself out of the packing case 

 and leave it behind, operating like a wedge, and spreading the 

 fore rim of the packing. Two longitudinal slits enable the pack- 

 ing readily to expand. 



