Of course the reader will remember that this was only an ordinary Clam, and not one of the giant race.
Below the shell are two very perfect instances of natural Pincers, each acting in a different manner, but on the same principle.
The Earwig is too familiar to need much description, but I may as well state that its pincers are not primarily intended as weapons, although they can be so used on occasion. (I was about to say, at a pinch, but refrain.) They resemble our ordinary pincers in that both blades move equally, and they are so completely under the control of their owner, that the insect uses them with a delicacy of touch that a lady’s fingers could hardly surpass. They are really tools, and not weapons, and are employed for the purpose of folding the wide and delicate wings under the tiny elytra.
There is another insect called the Scorpion-fly (Panorpa), the male of which is furnished with a pair of pincers at the end of a long and flexible tail, articulated just like the tail of a scorpion, and moved in exactly the same manner. It is but a little insect, but its gestures are so menacing as it flourishes its tail about, that non-entomologists may well be pardoned for being afraid of it. Moreover, small as are the pincers, they really can give a smart nip, and make themselves felt on the human skin.
If we want examples of exceedingly powerful pincers, we need only go to the Lobsters and Crabs, especially to the latter, whose claws are often of enormous thickness in proportion to the size of the animal. All those who have visited the seaside know how severe is the pinch of the common Green Crab, comparatively small though it be, and the same may be said of the river crayfish, which is, in fact, a lobster in miniature.
As to the lobster itself, fishermen are so well acquainted with the power of its claws, that they tie them together with string as soon as the animal is caught. Formerly they used to “peg” them, i.e. drive a wooden peg into the joint so as to prevent it from moving. This custom, however, is now prohibited by law on account of its cruelty.
The power of the Crab’s claws is so great that a bite from a large Crab will inflict a severe injury, and render a hand helpless. It has more than once happened that men who have been feeling for Crabs in the recesses of the rocks at low water have been seized, and seriously imperilled, not being able to release themselves from the gripe.
Indeed, it is said that there have been instances where the Crab has held so tightly, that the man has been drowned by the returning tide, no one having come to his assistance. I am, however, inclined to doubt this statement, thinking that the Crab would not be likely to remain in its hiding-place very long after the water came up. Still, that such an idea should be currently believed in many parts of England shows the estimation in which the gripe of the Crab’s claw is held.
TOOLS.
CHAPTER IV.
POLISHING TOOLS.—MEASURING TOOLS.
Files and Sand-papers.—The Sheffield File and its Structure.—The Equisetum, Mare’s Tail, or Dutch Rush.—Beauty of its Surface when seen through the Microscope.—Sand-paper.—Skin of Dog-fish, Skate, and Shark.—Skate-skin used for Sword-handles.—Distinction between the File and Sand-paper.—Measuring Tools.—The Plumb-rule and the Level.—Their Use in Tunnelling.—The Measure and its Uses.—The Two-foot Rule and the Tape Measure.—Ovipositor of Gall-fly.—Tongues of the Woodpecker, Wryneck, and Creeper.—The Spirit-level and its Uses.—Theodolite and Callipers in Nature and Art.—The Contouring-glass.—Pincers of Earwig again.—Jaws of Insects.—The great Sialis of Columbia.