This farm, as well as all those about Nyack, lies on the singular mass of sandstone included by a front of about five miles on the river. All the surrounding rocks are of other materials. This sandstone, when quarried, exhibits strata of a kind of red marl of many feet in thickness, lying between strata of the sandstone. The quarry-men throw it out of their way, and millions of loads are lying near the water's edge, so that in many places vessels can lie alongside a bed of it, and slide it on board. On Mr. Maxwell's farm, the former proprietor, desirous of making extensive hard walks through his garden, caused this marl to be put upon them about one foot deep. Soon after this was finished, the walks began to produce clover; the white in such profusion and persevering succession, that all prospect of using the paths in that condition was abandoned: they could not be kept in order by the hoe. Mr. Maxwell being strongly impressed by this occurrence, determined on applying it to the surface of his farm. I saw a field of corn of several acres which had been top-dressed this year with the red marl, now bearing not less than 80 bushels of shelled corn to the acre--as great a product as is obtained from the best city manure, costing at Nyack nearly 37 cents per load. I saw an upland field of wheat, on which, as an experiment, Mr. Maxwell had top-dressed with this marl a space of three rods by two, from which I pulled an average bunch of straw-stubble, that is more than double the size and weight of any like parcel of stubble, to be found in the whole field of several acres. Unfortunately the husbandman had cradled all the wheat indiscriminately, which prevented Mr. Maxwell from examining the separate product of the wheat. I should not hesitate to pronounce it a double product. Mr. M. top-dressed a field of oats with this marl, and the yield was 70 bushels per acre. He top-dressed a field of clover with it the third year from the seeding, and the product is heavier than the crop of the _second year_. This field was dressed with ten loads of marl per acre. The corn is large 12-row yellow, and the stalks are about 10 feet high. The corn-blades never curled during the late drought, while other fields all curled. The corn was worked with the hand-harrow once, with the cultivator twice, and was hoed twice. No plowing between the hills. Mr. M. thinks that in dry weather it is very injurious to run the plow through, for it cuts the smaller roots of the corn. He has tried 25 bushels of hickory ashes, against 25 of anthracite coal ashes, and found no perceptible difference in the result.