Near our halting place there stood a lofty
tower, whose illuminating apparatus threw a radiant, vari-colored light on
the dark surface of Lake Huron.
Upon expressing a desire to visit the Light Tower, Mr. James, who never
left any of our wishes unfulfilled, immediately made arrangements with the
keeper; and, accordingly, we were invited to intrust ourselves to his
guidance.
He informed us that the structure rested on a foundation consisting of a
concrete mass, nine feet below the water line. Having ascended four
flights of iron-wrought winding stairs, we reached the top of the circular
structure; it having a diameter of twenty-four feet at its base, and
rising to an elevation of fifty-seven feet.
With great interest we inspected the revolving lights, exhibiting an
ingenious piece of machinery, the invention of Finisterre and Barren in
Paris, and representing a value of $1,800. This apparatus for rotating
lamps is far superior to that for a fixed light.
The characteristic of the latter is to constantly illuminate the whole
horizon, requiring all the rays to fall simultaneously on the navigable
track, whereas the demands made of a revolving light, are not nearly so
great; only each point of the horizon being lighted at successive periods.
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