The hair ( on the Cramer bow ) is wider than the Corelli model but still narrower than a Tourte, the screw mechanism becomes standard, and more sticks are made from pernambuco, rather than the earlier snakewood, ironwood, and china wood, which were often fluted for a portion of the length of the stick.
22.
The best-known speculum is the bivalved vaginal speculum; the two blades are hinged and are " closed " when the speculum is inserted to facilitate its entry and " opened " in its final position where they can be arrested by a screw mechanism, so that the operator is freed from keeping the blades apart.
