PORT n.
which a fluid, as steam, water, etc., may pass, as from a valve to the interior of the cylinder of a steam engine; an opening in a valve seat, or valve face. Air port, Bridle port, etc. See under Air, Bridle, etc. -- Port bar (Naut.), a bar to secure the ports of a ship in a gale. -- Port lid (Naut.), a lid or hangi…
PRIMING n.
The carrying over of water, with the steam, from the boiler, as into the cylinder. Priming of the tide. See Lag of the tide, under 2d Lag. -- Priming tube, a small pipe, filled with a combustible composition for firing cannon. -- Priming valve (Steam Eng.), a spring safety valve applied to the cylinder of a steam eng…
PROJECTION n.
a cone tangent to the sphere, the point of sight being at the center of the sphere. -- Cylindric projection, a mode of representing the sphere, the spherical surface being projected upon the surface of a cylinder touching the sphere, the point of sight being at the center of the sphere. -- Globular, Gnomonic, Orthogr…
PSYCHIC; PSYCHICAL a.
the mind, or its functions and diseases; mental; -- contrasted with physical. Psychical blindness, Psychical deafness (Med.), forms of nervous disease in which, while the senses of sight and hearing remain unimpaired, the mind fails to appreciate the significance of the sounds heard or the images seen. -- Psychical c…
PUNCTUM n.
A point. Punctum cæcum. Etym: [L., blind point.] (Anat.) Same as Blind spot, under Blind. -- Punctum proximum, near point. See under Point. -- Punctum remotum, far point. See under Point. -- Punctum vegetationis Etym: [L., point of vegetation] (Bot.), the terminal cell of a stem, or of a leaf bud, from which new gro…