We were lately present at a trial of Cora-stock's Rotary Digger, at Flatbush, L. I. There were a number of gentlemen present, not the least interested of whom was Mr. Howe, famous as the inventor of the sewing machine. We shall not at present describe the machine further than by saying that it is a cylinder mounted with steel tines, and moving on wheels. These tines can be arranged so as to enter the soil to the depth of twelve inches, or even more. The machine can be thrown out of gear, so as to move readily and easily over any surface. The present implement, drawn by one pair of horses, broke, up and pulverized the soil full eight inches deep, and of the width of about three ordinary furrows; thus doing the work of three yoke of oxen with the plow, and doing it rapidly and well; much better, indeed, than it could be done by any plow now in use. The action of the machine resembles that of the spade. The soil in which it was tried was a compact loam, neither light nor heavy. The machine was followed about the field, and its operation watched with profound interest.

Some criticisms were indulged in, which were listened to by Mr. Comstock re-respectfully, and even eagerly, for he does not claim that the machine is yet as perfect as he can make it; some defects, indeed, he pointed out himself. We think (and said) that the number of tines might be reduced at least one-half with advantage to the work, and a great saving of friction. But Mr. Comstock noted all these criticisms at the time, and has gone home to perfect his machine. For simplicity, cheapness, and good work, we have seen no implement that has given us greater satisfaction, and few that have given as much. We think it is destined, when perfected, to make a revolution in plowing. We hope to see the day when soil can be thoroughly broken up and pulverized without a dead furrow.