nt, must yet be attained before the true
Plutonic zone, or that one in which there is no twilight whatsoever,
even upon the shortest day of the year, can be said to have been entered
by man. Of course, about the beginning and ending of this twilight, it
is very feeble and easily extinguished by even the slightest mists, but
nevertheless it exists, and is quite appreciable on clear cold days, or
nights, properly speaking. The North Pole itself is only shrouded in
perfect blackness from November 13 to January 29, a period of
seventy-seven days. Supposing that the sun has set (supposing a
circumpolar sea or body of water unlimited to vision) on September 24,
not to rise until March 18, for that particular point, giving a period
of about fifty days of uniformly varying twilight, the pole has about
188 days of continuous daylight, 100 days of varying twilight, and 77 of
perfect inky darkness (save when the moon has a northern declination) in
the period of a typical year. During the period of a little over four
days, the sun shines continuously on both the North and South Poles at
the same time, owing to refraction parallax, semi-diameter, and dip of
the horizon.

* * * * *

THE COLLINS LINE OF STEAMERS.

The breaking up of the Baltic, the last of the famous Collins line of
steamships, calls out a number of interesting facts with regard to the
history of the several vessels of that fleet. There were five in all,
the Adriatic, Atlantic, Pacific, Arctic, and Baltic. They were built and
equipped in New York. Their dimensions were: Length, 290 feet; beam, 45
feet; depth of hold, 311/2 feet; capacity, 2,860 tons; machinery, 1,000
horse power. In size, speed, and appointments they surpassed any
steamers then afloat, and they obtained a fair share of the passenger
traffic. A fortune was expended in decorating the saloons. The entire
cost of each steamer was not less than $600,000, and notwithstanding
their quick passages, the subsidy received, and the high rates of
freight paid, the steamers ran for six years at great loss, and finally
the company became bankrupt.

The Atlantic was the pioneer steamship of the line. She sailed from New
York April 27, 1849, and arrived in the Mersey May 10, thus making the
passage in about thirteen days, two of which were lost in repairing the
machinery; the speed was reduced in order to prevent the floats from
being torn from the paddle-wheels. The average