. The botanist's companion; or, Directions for the use of the microscope. Botany; Microscopy. 32 PREPARATION OF FOSSIL SECTIONS annealed to a straw colour. The pestle is merely a cylinder of steel, fitting the hollow mortar but loosely, and having a ledge or edging of an eighth of an inch projecting round it, but sufficiently raised above the upper surface of the mortar, so as not to come in contact while pounding the diamond. The point of the pestle ought only to be hardened and annealed to a straw colour, and should be of course convex, fitting the opposing and equal con- cavity of the morta

- Image ID: RH97GA
. The botanist's companion; or, Directions for the use of the microscope. Botany; Microscopy. 32 PREPARATION OF FOSSIL SECTIONS annealed to a straw colour. The pestle is merely a cylinder of steel, fitting the hollow mortar but loosely, and having a ledge or edging of an eighth of an inch projecting round it, but sufficiently raised above the upper surface of the mortar, so as not to come in contact while pounding the diamond. The point of the pestle ought only to be hardened and annealed to a straw colour, and should be of course convex, fitting the opposing and equal con- cavity of the morta
Library Book Collection / Alamy Stock Photo
Image ID: RH97GA
. The botanist's companion; or, Directions for the use of the microscope. Botany; Microscopy. 32 PREPARATION OF FOSSIL SECTIONS annealed to a straw colour. The pestle is merely a cylinder of steel, fitting the hollow mortar but loosely, and having a ledge or edging of an eighth of an inch projecting round it, but sufficiently raised above the upper surface of the mortar, so as not to come in contact while pounding the diamond. The point of the pestle ought only to be hardened and annealed to a straw colour, and should be of course convex, fitting the opposing and equal con- cavity of the mortar. The purpose of the projecting ledge is to prevent the smaller particles of diamond spurting out when the pestle is struck by the hammer. Mr. Bryson has contrived an instrument for slitting fossils. The instrument is placed on the table of a common lathe, which is, of course, the source of motion. (Fig. 19.) It consists of a Watt's parallel motion.. Fig. 19. with four joints, attached to a basement fixed to the table of the lathe. This base has a motion (for adjustment only) in a horizontal plane, by which we may be enabled to place the upper joint in a parallel plane with the spindle of the lathe. This may be called the azimuthal adjustment. The adjustment, which in an astronomical instrument is called the plane Fig. 19. Mr. Bryson's instrument for slitting fossils.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Balfour, John Hutton, 1808-1884. [from old catalog]. Edinburgh, A. and C. Black

Similar stock images