this connection, there is a story afoot
that a hammer was kept upon the mantelpiece of a well-known hotel in
Salisbury, which was reserved for the use of those intending to see
Stonehenge, who might be wishful to bring back some convincing
evidence of their visit.

In all probability these foreign stones originally numbered
forty-five. To-day there are but thirty.

A complete lithology of the stones made by the late Professor J.W.
Judd, in 1901, reveals the following rocks as comprising those used in
the construction of Stonehenge.

1. _Sarsens._--Coarse and fine-grained Sandstone similar to the
Woolwich, Reading, or Bagshot beds. This stone is used for
the Trilithons, Hele Stone, a recumbent stone known as the
"Slaughtering Stone," and two small stones set north-west
and south-east of the circle. It is of local origin.

2. _Ophitic Diabase._--(Some porphyritic.)

3. _Highly altered basic Tuffs, and agglomerates_ (calcareous
chloritic schists).--Only one stump now remains.

4. _Altered Rhyolites and Dacites._--Only fragments of this rock
have been revealed during Mr. Gowland's excavations in 1901.
At one time doubtless there was a whole upright of this
material, but its striking appearance and fracture has
probably led to its demolition by generations of _souvenir_
hunters. Other fragments have been found in the barrows once
within sight of Stonehenge, but now destroyed by cultivation.

5. _Sandstones, Grits, and Quartzites._--The "Altar-Stone" belongs
to this class. It is interesting to note that Professor
Maskelyne has pointed out the similarity between the Altar
Stone at Stonehenge, and the "Stone of Destiny" in the
Coronation Chair at Westminster Abbey.

6. _Grey Wackes._--Fragments only of these stones have been
discovered among the chippings incidental to the dressing of
the stones before erection.

Their absence at the present day is not a matter for surprise, as
stones of this class weather badly, and when exposed to the
action of frost and cold rapidly disintegrate.

7. _Argillaceous Flagstones and Slates._--As in the case of the
Grey Wackes, fragments only of these stones exist to tell the
story of the uprights which have vanished under atmospheric
changes.

8. _Glanconitic Sandstone_ (possibly Upper Greensand?).--Traces of