260 JOURNAL OF THE PLYMOUTH INSTITUTION. 
plastered with the same mortar as that with which the wall is 
built. Although they cannot at the present time be said to be 
open from end to end, I think there is no doubt that they are 
really so, and that the obstruction in one or two places, which 
prevents a long rod being passed through, is caused by the deposit 
of stones, the handiwork of the youth of Plympton. 
Connected with these openings are some others, which I may 
refer to. Running quite through the thickness of the wall, and 
in some places apparently crossing the others at right angles, are 
several smaller holes, round in shape, about four inches in 
diameter, extending from the inside to the outside of the ruin. 
A mysterious connection between these holes and the larger ones 
has been assumed; and if one theory could possibly be correct, 
that the latter were passages for soldiers to and from the different 
parts of the building, they would certainly be useful in giving the 
unfortunate traveller a little air in his journey through an opening 
seventeen inches by ten. The larger holes are also stated to 
communicate with a secret passage which formerly existed between 
the Castle and the Priory, in confirmation of which certain 
Plymptonians will assure you that cats put into one of these 
holes have been known to turn up at the Priory. Other sug- 
gestions are, that the openings were used for sending missiles 
through—but how this was done has never been explained—as a 
means of ventilation, and as a kind of speaking tube for trans- 
mitting messages from one part of the keep to another. All these 
explanations are wide of the mark, and there is really no difficulty 
at all in the matter. The fact is, that these holes were originally 
filled with timber balks, intended to strengthen and support the wall 
upon the somewhat uncertain foundation of the mound. This 
plan was frequently resorted to by the Norman builders, especially 
when the work was placed upon an artificial foundation ; the ties 
were enclosed in the masonry, the mortar was freely used, and ran 
down into the interstices, and formed a sort of casing round the 
timber. In course of time the timber decayed, leaving the 
hollow spaces as we now see them. Similar cavities have been 
found elsewhere, and there can be no doubt that this is the ex- 
planation. ‘At Lincoln, when the foundations of some of the 
Norman work were laid open for repairs, they were found to be 
worked in with a sort of framework of timber tying the whole 
together,” showing that this mode of construction was adopted as 
