this transition limestone, and proved to be 564 feet above its
lowest visible bed (no other rock alternating with, or appearing
between it), or about 600 feet above the level of the sea? Over
the thin layer of vegetable mould which covered the limestone,
were scattered large rounded blocks of a dark-coloured, compact
basalt, glistening with crystals of horneblende, generally covered
with a moss ( kypnum intricatum) on the part nearest the soil,
and with lichens (patellaria ventosa and urceolaria occellata) on
the upper surface11.
Ascending the hill which appears in the drawing, to the eastern
c Barometer 741.50, thermometer 20, thermometer detached 19£ cent.
d I found three other lichens, which were not sufficiently advanced for me to
determine ; and a fourth, which I can only refer to the idiothalames heterogenes of
Acharius, having been unable to afford any works on cryptogamia, and my memoranda
being too limited to decide on species, or even genera in all cases. I intend, at ¿resent,
to send home drawings of the new genera and species of the ‘zoology and botany of
the parts of Africa I may be enabled to visit ; and I hope" to pérsevère in this plan
throughout my travel, even should it be extended to some years, by a reasonable
support on the part of the government. It takes away very much from the usefulness
of a travel, when it is attempted :to save the trouble of making drawings, by substituting
for that concise description of the object, which will always suffice with an
accurate figure, a verbose detail of tiresome minuti®, wholly uninteresting, and frequently
unintelligible, without the aid of thé pencil. The only probable difficulty is£
that no publisher will undertake thé expense of having all thesè figures engraved, and
that they may thus be lost to the naturalist and others,"who would feel an interest in
referring to them as illustrations of the text. Contemplating this probability, I determined
to obviate it in some degree, by regularly transmitting a s'et of these drawings
to Sir H. Davy, to deposit wherever he considers they may be most readily consulted
by the naturalists of my own country, who will always find them numbered so as, to
correspond with the references in the text of my travels. I shall also transmit a
duplicate set of these drawings to Baron Cuvier, to be deposited for the same purpose
in the library of the French Institute. The two sets of 107 figures (several of which
are coloured) referred to in this first pari, are forwarded .with the manuscript.
Mrs. Botvdich, .having reached England before the printing of the manuscript, has withdrawn the
above-mentioned figures, and published the greater number of them in the work itself.— E d.
entrance of the aqueduct, I found above the limestone (but without
witnessing the contact), a basalt composed of a dark grey feldspath,
full of ochry red and yellow streaks and spots, mixed with shining
scales of oxide of iron, and having a grariite-like texture and
appearance; it seemed to descend in sheets, to the south. The
glass disclosed innumerable small grains of green earth, and it
passed into decomposing masses so thickly speckled with it, as to
assume the appearance of a porphyritic sandstone. Examining
the specimens I had separated from the blocks of basalt on the
opposite side, with a glass, I found they presented the same
spotted structure, with the addition of small crystals of hornblende.
The upper part of a decomposing mass of this basalt, dipping
towards the south, contained laminas of talc passing into steatite,
and terminated eastward in a deposit of a deep-red ferruginous
earth. As I ascended to a wall, close behind the statue at the
entrance of the aqueduct, I found several blocks of basalt, similar
to those on the western height, and creeping through a large hole
in this wall to examine a hillock of the decomposing basalt (the
exterior surface of which yielded to the finger, and was profusely
speckled with green-earth), I picked up several loose pieces of
amygdaloid: the small oval cavities were generally filled with a
dull yellowish earth, and the cellular mass was of the same speckled
basalt. In one of the small hillocks there was a portion of conglomerate,
composed of earthy and crystallized lime, minute scales
of talc, and blunt fragments of red feldspath; but the mass was
so small, so abruptly discontinued, and so nearly parallel with the
basaltic rock by the side of it, that I can say nothing of their
relative age. The dip of the limestone seemed to be to the
eastward, for its depth diminished in that direction; and it disappeared
on that side, at about 400 feet below the height to which
it reached on the western side. I had not time to follow it south-
C