in touch with this officer and explained the work he had done with
Lieutenant Whiting. Fisher, deeply interested, invited the painter to
deliver a series of lectures to the officers of the submarine flotilla
at the Brooklyn Navy Yard.

With the aid of a Maxwell disk--a wheel upon which colored cardboard is
placed and then revolved--he demonstrated the difference between paint
and light, as set forth in a book on the chemistry of color by the late
Ogden N. Rood, of Columbia. He showed, for example, that yellow and blue
in light make white, while yellow and blue in pigment make green. The
bird colored blue and yellow will be a dull gray at a distance of 100
feet, and will blend perfectly against the dull gray of a tree-trunk at,
perhaps, a less distance. The parrot of red, green, and violet plumage
turns gray at 100 feet or more, the eye at that distance losing the
ability to separate the three color-sensations.

It is upon this principle, then, that ships painted in several varieties
of tints and shades form combinations under different lights that cause
them to waver and melt into the sea and sky. They _seem_ to melt, to be
more explicit, because the craft so painted is surrounded by tints and
shades that are similar to those employed in painting the craft.

Vessels thus painted, as seen at their docks, present a curious aspect.
At their water-lines, and running upward for perhaps twenty feet, are
green wave-lines, and above, a dappled effect of red, green, and violet,
which involve not only the upper portions of the hull, but the
life-boats, masts, and funnels.

This, then, as said, was the American idea as first applied by Mr.
Mackay, and which would have been greatly amplified had not listening