The _Railway and Locomotive Engineering_ says:
Some of the principal requirements of a locomotive headlight are
that the light from it shall be powerful enough to illuminate
the track far enough ahead to permit of an emergency stop;
that the light shall not be so brilliant as to cause temporary
blindness or bewilderment in those upon whom it falls; that in
the matter of signal observance it must not alter or modify the
colors of the lesser lights which come into its field, and that
it shall be as effective a form of light as can be devised for
foggy or snowy weather.
(1507)
When Moses returned from communion with God his face shone so brightly
that a veil was needed. There was another transfiguration which is
the result not of glory reflected but of grace transfused. “Be ye
transformed (lit. transfigured) by the renewing of your mind,” says the
apostle.
The visitor to the beautiful church of St. Paul without the
walls at Rome is sure to be asked by the sacristans to notice
the wonderful columns of pure alabaster which are among the
splendors of that edifice. The guide brings a lighted taper
which he places behind one of these massive pillars. The
translucent alabaster immediately glows with the light that
seems to play all through it with lambent effulgence. The solid
mass glorifies the flame, as the flame illumines the solid
substance. (Text.)
(1508)
See LIGHT.