between England and America was ever lost on that formidable point.

It appears to me by no means unlikely that, with the improvement of
instrumental power, and of the means of ascertaining the ship's time
with exactness, as great an advance beyond the present state of art and
science in finding a ship's place at sea may take place, as was effected
by the invention of the reflecting quadrant, the calculation of lunar
tables, and the improved construction of chronometers.


BABBAGE'S DIFFERENCE MACHINE.

In the wonderful versatility of the human mind, the improvement, when
made, will very probably be made by paths where it is least expected.
The great inducement to Mr. Babbage to attempt the construction of an
engine by which astronomical tables could be calculated, and even
printed, by mechanical means and with entire accuracy, was the errors
in the requisite tables. Nineteen such errors, in point of fact, were
discovered in an edition of Taylor's Logarithms printed in 1796; some
of which might have led to the most dangerous results in calculating a
ship's place. These nineteen errors, (of which one only was an error of
the press), were pointed out in the _Nautical Almanac_ for 1832. In one
of these _errata_ the seat of the error was stated to be in cosine of
14° 18' 3". Subsequent examination showed that there was an error of one
second in this correction; and, accordingly, in the _Nautical Almanac_
of the next year a new correction was necessary. But in making the new
correction of one second, a new error was committed of ten degrees.
Instead of cosine 14° 18' 2" the correction was printed cosine 4° 18' 2"
making it still necessary, in some future edition of the _Nautical
Almanac_, to insert an _erratum_ in an _erratum_ of the _errata_ in