next ally. This is particularly true of basalt. I subjoin an account of the succession of strata, under which the grotto at Down-hill is formed.

1. Two undistinguishable strata of very confused basalt, partly columnar, more generally shivered, resting on a base of ochre, graduating into trapp,

2. Red ochre, somewhat branching into veins,

3. Small tables of basalt, mixed and alternated with earthy trapp,

4. Ochre,

5. Trapp, with basalt veins of ochreous and zeolitic matter, with masses of hard table-basalt,

Feet.

60

1

70

1

14

6. Trapp, with veins and strata of zeolite, blending at bottom into soft, coarse, friable basalt,

6

7. Trapp, indistinctly blended with basalt, changing by shades, the midmost tabular,

4

8. Rude, coarse basalt, with blotches and blebs of zeolite, 9. Black basalt, involving masses of trapp,

10

12

178

The altitude of the rock, on which stands the temple, and which overjuts its base, is 168 feet.

In descending by the zig-zag path, the order of the strata is as follows:

1. Soil and rubble.

2. Amorphous basalt.

3. Indurated and coarse rock tallow or soap-stone.

4. Steatites.

5. Basalt.

6. Trapp.

7. Tabular basalt.

8. Confused basalt with trapp, abounding in crystals of zeolite,

and in soap-stone.

9. Trapp.

N

10. Basalt, with exsudations of a coarse, calcareous substance, somewhat approaching to steatites, and incrusting the external surfaces, a species of stalactites.

11. Reddish trapp, veined with zeolite.

12. Shivery basalt, with veins of steatites.

13. Steatites.

14. Trapp.

The section of Lord Bristol's road lays open the following suc

cessions :

1. Soil and rubble, both rust-coloured.

2. Ochreous basalt, intersected by reclined veins of olive-brown steatites, and also by veins of red ochre. All these are occasionally incrusted with the same calcareous exsudations, as are mentioned above.

3. Basalt, with veins of hard reddish ochre, which pass each other in various angles.

4. Very friable trap inclining to ochre.

5. Soap-stone, almost hid by the sand, which is blown up this

ravine.

Observations.- 1st. The above-mentioned exsudation seems to arise from the calcareous matter of the cores of the rock, which being penetrated by water, the veins of the strata yield the lime, to be carried off in a state of solution. I have found masses of calcareous spar, mixed with zeolite, in considerable branches and veins through basalt.

2nd. The uppermost stratum basseting to the west, as viewed from the sea, in an angle of four or five degrees, is longer or shorter in dying off, or in conforming to the plane of the horizon above, in proportion to its thickness; sometimes ending in an abrupt segment of the stratum, sometimes melting gradually, so as to correspond with the general level of the surfaces above.

At the second head-land of Magilligan, we find

The rest covered with sand and bent-hills.

The strata, measured with a line let down from above, were in

depth,

The sand, by conjecture,

The elevation of this perpendicular,

Feet.

138 64

202

The measurements of the third head are taken, by the thickness of each stratum separately, by a micrometer compared with a quadrant. 1. Basalt, basseting abruptly,

2. Second stratum, which bassets about fifty yards beyond the former, to the west,

3. Regular stratum of red ochre,

4. Shapeless basalt,

5. Repetition of the red ochre,

6. Friable basalt,

7. Red ochre repeated,

8. Rude basalt, with trapp,

10

11

1

75

1

32

1

53

22

Sand blown against the base,

Total altitude of this perpendicular,

206

Observation.-In climbing to the base of the perpendicular, you encounter the appearance, at least, of danger; for, the ochre, steatites, trapp, and other mixed and soft substances, having yielded to the elements, leave the bases of the harder strata jutting over, and seemingly ready, and as certainly doomed, to fall. This is one of the sure, though slow and silent operations, by which the loftiest solids of the earth are continually approaching to basement of the ocean.

I shall now give a measurement, taken in the upward direction

above the limestone.

1. In contact, intermixed with soft, reddish-brown ochre, nodules of flint, and fragments of limestone, taken together,

2. Brown, soft substance, apparently intermediate, between steatites and trapp,

3. Shapeless basalt,

4. Trapp, abounding in zeolite,

5. Shapeless basalt,

6. Ditto,

7. Red ochre,

8. Confused basalt,

9. Red ochre,

10. Loose incoherent basalt,

11. Trapp,

12. Brown ochre,

13. Confused and table basalt,

14. Incoherent basalt,

15. Compact basalt, (the basset irregular,) about

Total above the lime,

20

9

40

1781

Observations.-1. Sometimes it is basalt, sometimes trapp, or any other of the accompanying strata, which bassets, (just as they respectively reach to the summit,) in advancing westward with an ascending plane.

2. The medium, in contact with the limestone and basalt, is a jumble of reddish ochre, soft, brownish matter, including nodules of flint simply, or in masses of nodules agglutinated. The flint has no mark of calcination, but is shivery and shattered in several places; it even contains shells, though immediately in contact, under the ba saltic mixture. I have several specimens from various contacts in my collection.

3. To a spectator standing below, it may seem as if the strata sometimes had an inclination different from that, which has been mentioned. This happens, when the face of the strata retires inward, and is only a deception of sight, which those who are acquainted with the rules of perspective, will easily understand.

4. It sometimes happens, that the western termination of a stratum, which comes to basset in its turns, does not exhibit its boundary by any perpendicular line, but dies away almost in an horizontal line. I remarked this in the cases of those strata, which are of the softer materials: their jutting and angular extremes have gradually yielded to the elements, and thus have softened down into a plane.

Observations on Mount Salut.

This house was formerly the resort of fashionable invalids; it was built by a subscription, under the patronage of Miss Tompkins, a beauty of the last century. The intention was to combine sea-bathing and goat's whey with (what is no less salutary to the convalescent) cheerful society.

The avenue, though in itself a steep ascent, brings you only to the foot of the mountain: the next acclivity is of rocky pasturage, formerly the browsing of the goat, and now but a scanty bite for the native cow. This rocky matter found so low is an object, which must be accounted for. On the further side, after topping it, we find a deep ravine, which separates it from the next ascent. In fact, the whole of this mass is one of those kinds of avalanches, already noticed as torn away from the original strata above.

The escarpment of the stratified mountain is encumbered, near its base, by the rocks, which have tumbled from the precipice: the strata, above this heap of ruins, are subjoined.