ON KENT’S CAVERN, DEVONSHIRE. 45 
7th. In the year 1831 (authority Herr yon Midler) the white spot was 
seen only near the time of full moon, almost as white in the middle as at the 
edges. 
Sth. In the years 1867 and 1868 the white spot appeared shortly after 
sunrise and disappeared a little before sunset, and was frequently observed 
to have a brighter nucleus, instead of being almost as white in the middle as 
at the edges. 
9th. In the year 1831 (authority Herr von Midler) the interior shadow 
was perceptible until the sun attained an altitude of 30°. 
10th. In the years 1867 and1868 the small crater-opening has been seen as 
a small black spot, rather west of the centre of the white spot, long after 
the terminator has passed Linné, but the usual interior crater-shadow has 
not been seen except with comparative low solar altitudes. 
Fourth Report of the Committee for Exploring Kent’s Cavern, Devon- 
shire. The Committee consisting of Sir Cuartes Lye, Bart., 
Professor Puinuirs, Sir Jonn Lussock, Bart., Mr. Joun Evans, 
Mr. Epwarp Vivian, Mr. Grorce Bus, and Mr. Witiram Pxn- 
GELLY (Reporter). 
In their Third Report, presented to the Association in 1867, the Committee 
stated that the Cavern consists of two parallel series of chambers and gal- 
leries, having, approximately, a north and south direction; that their re- 
searches had been confined to the Eastern Series, in which the North-east 
Gallery, the Vestibule, the Passage of Urns, the Great Chamber, and the 
Gallery had been completely explored to the depth of 4 feet below the base 
of the Stalagmitic Floor ; that the investigation of the Lecture Hall had been 
begun, but that the greater part of it, as well as the entire South-western 
Chamber and the North and South “Sally Ports,” remained untouched. 
The year 1867-68 has been devoted to the Lecture Hall and South-west 
Chamber. The exploration of the former has been completed, and, so far as 
an estimate can at present be formed, the latter will have been thoroughly 
investigated in about two months from the present time. There is, however, 
some uncertainty on this question, since the further end of this Chamber is 
now closed with an enormous accumulation of stalagmite ; and it is not im- 
probable that when this is removed the apartment may prove to be much 
larger than is at present supposed. The Superintendents of the work incline 
to the opinion that a gallery will sooner or later be laid open here, which 
will lead into the Western Series of Chambers and Galleries. There is at 
present but one known channel of communication between the two series— 
that leading westward out of the Vestibule, near the opposite or northern 
end of the Cavern. 
The Committee continue to follow the mode of exploration laid down at 
the commencement of the work, and described in detail in their First Report, 
presented in 1865. The deposits are excavated in successive foot-parallels, 
and each parallel is removed in foot-levels, to the depth of 4 feet beneath 
the lower surface of the Stalagmitic Floor. In no instance has anything like 
a continuous limestone bottom of the Cavern been reached; but a depth 
greater than 4 feet would be incompatible with convenient, economical, trust- 
worthy working, as it would be necessary to be continually putting up and 
