CRANE FOR RAISING MARL BY HORSE POWER. 291 



suspended through winter. In such cases, it is better to bestow 

 more labour to obtain security. Under such circumstances perpen* 

 dicular pits should be sunk first through the over-lay and then the 

 marl. If not too great a height, the marl, as dug, should be 

 thrown to the top of the remaining firm earth, there to be thrown 

 into and removed by the carts. When the digging is carried so 

 low that the throwing exceeds 10 feet in perpendicular height, a 

 scaffold should be made, or a shelf of marl left, at the side 

 of the pit next to which the carts approach, and at a convenient 

 height for the remainder of the digging. The lower marl will be 

 thrown first upon the scaffold, thence to the surface of the ground 

 above, and then into the carts. Thus, the marl may be thrown up 

 from the bottom of the bed, if that be not more than 20 feet be- 

 low the surface, for loading. The length and breadth of such pits 

 should not be greater than to permit each pit to be finished in a 

 few days after its commencement. Then an adjoining like space 

 may be uncovered, the earth being thrown into the previous dig- 

 ging, and the marl excavated in like manner. Should a flood of 

 rain-water, or the caving in of wet earth fill such a pit, when the 

 digging had not been sunk but a few feet, the damage may be 

 remedied and the remaining marl saved. Or if but a few feet 

 thickness of marl be left, and is covered by earth or water in 

 tooxgreat quantity to be worth clearing out, then the loss of the 

 bottom marl will not be very important. 



For such situations as these, in some cases lifting machines have 

 been used successfully. One used by Win. Carmichael, Esq., of 

 Maryland, was described by him in a communication to the Far- 

 mers' Register, as follows : 



" In your ' Essay on Calcareous Manures,' you give instructions 

 for digging and carting marl. This method I pursued for many 

 years, but found the labour hard on my hands, and tedious. Marl 

 here is generally found in deep ravines or in wet grounds. My 

 operations have been slow, from the difficulty of making firm and 

 lasting ways, and the labour of ascending steep hills. Last winter 

 I made a model, and this spring I built a machine for raising marl, 

 to be worked by a horse. I have been using it to advantage, and 

 now send you a draught of it, as it may be useful to those 

 who have wet marl pits like mine. By means of a pump to throw 

 off the water, pits may be worked at a considerable depth ; and 

 even if marl is dry, but lies deep, I think the crane might be used 

 to advantage. I use? two boxes, and by means of hinges and a 

 latch the marl is discharged from the bottom. I have double 

 blocks; the rope passes through the swoop about eighteen inches 

 from the end, and runs down to the post which supports the swoop, 

 and passes through it on a small roller, and in like manner through 

 the next post to the cylinder, to which a reel is attached to increase 

 the motion. The post which holds the swoop and the cylinder, 



