Botanical specimens : particular directions for collecting and preserving specimens of plants : extracted from an unpublished treatise on practical botany / by John L. Riddell.

  • John Leonard Riddell
Date:
[1834?]
Catalogue details

Licence: Public Domain Mark

Credit: Botanical specimens : particular directions for collecting and preserving specimens of plants : extracted from an unpublished treatise on practical botany / by John L. Riddell. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    A, the bottom piece. B, the top piece. C, the axle. The bottom and top pieces may be 20 inches long, by 14 wide; 18 by 12 may do. They should be made from a seasoned board H E P M near an inch in thickness, possessing the requisite strength, and not liable to warp. The end pieces, I, H, J, are intended for maintaining the board a few inches from the floor, for the convenience of attaching or removing loops of rope. D, E, are the projecting ends of a strip of strong timber attached to the board beneath, over which the loops of rope pass. The ends of the longitudinal strip G F, are often useful in assisting to confine the lever soon to be mentioned. Transversely across the top piece and near the middle, two thin strips of board are to be strongly nailed, leaving an intervening channel or groove an inch in width. The axle is to lie in this groove, and if that be of iron, or any stronger materia] than wood, the trans- verse strips may be approximated still nearer with advantage.
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