yal Commission of Castilian Ecclesiastics.

"Young gentlemen, I resume my remarks on the passage of a shot _in
vacuo_, which remarks were interrupted yesterday by general quarters.
After quoting that admirable passage in 'Spearman's British Gunner,' I
then laid it down, you remember, that the path of a shot _in vacuo_
describes a parabolic curve. I now add that, agreeably to the method
pursued by the illustrious Newton in treating the subject of
curvilinear motion, I consider the _trajectory_ or curve described by a
moving body in space as consisting of a series of right lines,
described in successive intervals of time, and constituting the
diagonals of parallelograms formed in a vertical plane between the
vertical deflections caused by gravity and the production of the line
of motion which has been described in each preceding interval of time.
This must be obvious; for, if you say that the passage _in vacuo_ of
this cannon-ball, now held in my hand, would describe otherwise than a
series of right lines, etc., then you are brought to the _Reductio ad
Absurdum_, that the diagonals of parallelograms are----"

"All hands reef top-sail!" was now thundered forth by the boatswain's
mates. The shot fell from the professor's palm; his spectacles dropped
on his nose, and the school tumultuously broke up, the pupils
scrambling up the ladders with the sailors, who had been overhearing
the lecture.

CHAPTER LXXXIV.

MAN-OF-WAR BARBERS.

The allusion to one of the ship's barbers in a previous chapter,
together with the recollection of how conspicuous a part they enacted
in a tragical drama soon to be related, leads me now to introduce them
to the reader.

Among the numerous artists and professors of polite trades in the Navy,
none are held in higher estimation or drive a more profitable business
than these barbers. And it may well be imagined that the five hundred
heads of hair and five hundred beards of a frigate should furnish no
small employment for those to whose faithful care they may be
intrusted. As everything connected with the domestic affairs of a
man-of-war comes under the supervision of the martial executive, so
certain barbers are formally licensed by the First Lieutenant. The
better to attend to the profitable duties of their calling, they are
exempted from all ship's duty except that of standing night-watches at
sea, mustering at quarters, and coming on deck when all hands are
called. They are rated as