. The book of the farm : detailing the labors of the farmer, steward, plowman, hedger, cattle-man, shepherd, field-worker, and dairymaid. Agriculture. 386 THE BOOK OP THE FARM AUTUMN. Fig. 4] 7. in being broader in the blade, and longer wiihal, but in curvature it resembles the former; and its chief difference lies in being ground on both sides, to form a fine and thin sharp edge. Like the toothed sickle, the blade has undergone various improvements; and Mr. Sorby's cast-steel Bwedge-blade is also extended to the sniooth-edgcd sickle. (2230.) In the formation of the sickle, the curvature of th
. The book of the farm : detailing the labors of the farmer, steward, plowman, hedger, cattle-man, shepherd, field-worker, and dairymaid. Agriculture. 386 THE BOOK OP THE FARM AUTUMN. Fig. 4] 7. in being broader in the blade, and longer wiihal, but in curvature it resembles the former; and its chief difference lies in being ground on both sides, to form a fine and thin sharp edge. Like the toothed sickle, the blade has undergone various improvements; and Mr. Sorby's cast-steel Bwedge-blade is also extended to the sniooth-edgcd sickle. (2230.) In the formation of the sickle, the curvature of the blade is a point of more importance than to a careless observer may appear; and though the ordinary reaper is seldom qualified to judge in this matter, he may feel pleased to be informed that there is a certain curvature that will give to the muscles of his right arm the least possible for exertion, while there are other curves that, if given to the blade of the sickle, would cause him to expend a great amount of un necessary exertion in the arm, and a consequent unnecessary fatigue would follow. Fig. 417 which represents the smooth-edged sickle, has a curvature ap- proaching very near to that which, in tliix in.«trument, may be termed the curve of lenxl exertion ; and throughout that portion of the sickle that performs the cutting process, it this peculiar |>roperty, from the following circumstance, that lines diverging from the center of the handle of the sickle at <?, and intersecting the curve of the cutting-edge, all the diverging lines will form equal angles with the tangents to the curve at the points of intersection. This property gives to the cutting-edge a uniform tendency to cut at every point in its length, without any other exertion than a direct ptt/l upon the helve ; were the curvature less at any point, a pressure of the hand would be re- quired to keep the edge to the work, and were the curvature greater at any point, or on the whole,
Size: 1375px × 1817px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1850, booksubjectagriculture, bookyear
