|
| 60 | 0.866 | 13.00 | 27.7 |
| 70 | 0.940 | 14.09 | 25.5 |
| 80 | 0.985 | 14.77 | 24.4 |
| 90 | 1.000 | 15.00 | 24.0 |
+-----------+-------------+-----------------------+---------------------+

Now this is the point which, it should seem, ought to be the business of
experimenters to establish; it being proposed, as we are informed, to
swing, in different latitudes, freely suspended pendulums, over horizontal
dials, or circular tables, properly graduated, similarly to the horizons of
common globes; and to note the _apparent_ variation of the plane of
oscillation of the pendulums with respect to the graduated dials; these
latter serving as representatives of the horizon. For the hypothesis is (as
I understand it), that the pendulums will continue to swing each of them
severally in one invariable vertical plane fixed in free space, whilst the
horizontal dials beneath, by their rotation, will slip away, as it were,
and turn round in _azimuth_, from under the planes of the pendulums.

It should seem to be imperative on those who wish to put this experiment to
proof, to give all possible attention to the precautions suggested in the
excellent paper that appeared on the subject, on Saturday, April 19, in the
_Literary Gazette_, copied also into the _Morning Post_ of Monday the 21st.
To my mind, the experiment is beset with practical difficulties; but even
should the matter {372} be satisfactorily made out to those best capable of
judging, I cannot readily conceive of an experiment less likely than the
above to carry conviction to the minds of the wholly unlearned of the
rotation of the earth.

I perceive that B.A.C., in the _Times_ of April 24, avows his determined
scepticism as to the virtue of the experiment.

ROBERT SNOW.

* * * * *

MINOR QUERIES.

_William ap Jevan's Descendants._--In Burke's _Landed Gentry_, p. 1465.,
mention is made of William ap Jevan, "an attendant upon Jasper Duke of
Bedford, and afterwards upon Hen. VII.;" and of a son, Morgan Williams,
ancestor of the Cromwells. Will some correspondent oblige by giving a
reference to where any account may be met with of any other son, or
children, to such William ap Jevan, and his or their descendants?

W. P. A.

"_Geographers on Afric