The leaf of the fore-sight has a pinhole, and that of the tangent sight cross-wires for fine reverse laying.
From a pinhole burner, fed through a cavity C, one side of which is closed by a membrane m; on the other side of the membrane is another cavity C', which is put into connexion with a source of sound, as, for instance, a Helmholtz resonator excited by a fork of the same frequency.
Of water, issuing from a pinhole steatite burner.
Above a pinhole burner and igniting the gas above the gauze.
If a jet of water issues at an angle to the horizontal from a round pinhole orifice under a few inches pressure, it travels out as an apparently smooth cylinder for a short distance, and then breaks up into drops which travel at different rates, collide, and scatter.
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