ung ladies should ramble about the neighbourhood in
search of flowers and plants, under the care of Lewis, until two
o'clock, at which hour all were to assemble at the Montanvert hotel for
luncheon, Captain Wopper and Lawrence resolving to remain and assist, or
at least observe, the Professor. The former, indeed, bearing in mind
his great and ruling wish even in the midst of scientific doubt and
inquiries, had suggested that the latter should also accompany the
ladies, the country being somewhat rugged, and the ladies--especially
Miss Emma--not being very sure-footed; but Lawrence, to his
disappointment, had declined, saying that the ladies had a sufficient
protector in the gallant Lewis, and that Miss Emma was unquestionably
the surest-footed of the whole party.

Lawrence therefore remained, and, at the Professor's request,
accompanied the party who were to fix the stakes on the ice.

As this operation was attended with considerable difficulty and some
danger, we will describe the process.

Finding that the spot which he had first chosen for his observations was
not a very good one, the Professor changed his position to a point
farther down on the steep sloping rocks that form the left bank of the
Glacier des Bois. Here the theodolite was fixed. This instrument as
even our young readers may probably know, is a small telescope attached
to a stand with three long legs, and having spirit-levels, by means of
which it can be fixed in a position, if we may say so, of exact flatness
with reference to the centre of the earth. Within the telescope are two
crossed hairs of a spider's-web, so fine as to be scarcely visible to
the naked eye, and so arranged that their crossing-point is exactly in
the centre of the tube. By means of pivots and screws the telescope can
be moved up or down, right or left, without in the smallest degree
altering the flatness or position of its stand. On looking through the
telescope the delicate threads can be distinctly seen, and the point
where they cross can be brought to bear on any distant object.

Having fixed the instrument on the rocks quite clear of the ice, the
Professor determined the direction of a supposed line perpendicular to
the axis of the glacier. He then sought for a conspicuous and
well-defined object on the opposite side of the valley, as near as
possible to that direction. In this he was greatly helped by Captain
Wopper, who, having been long accustomed to look-out wit