122 
C. R. Wilson- 
-Topography of old Fort William. [R 0 . 2, 
bastion, and so vitiates its whole representation of this corner of the fort. 
In the case of the cross walls it is not easy to check the errors of the 
plan by actual excavation, for we cannot always expect to find trace of 
the cross walls which may have been very slightly constructed. As a 
matter of fact only two cross walls have been actually discovered by ex- 
cavation. One of these dd v was found by Mr. Bayne in 1883 and was 
again brought to light by me in 1891. This wall is 1 ft. 6 in. thick and 
is 145 ft. 6 in. from the centre of the east gate. Mr. Bayne thought 
that this wall was the north wall of the Black Hole, I shall show that 
it is probably the south wall of the prison. The other cross wall (56 ) 
is a much more solid wall than the wall just described (dd,). It is 
ft. thick and is at a distance of 100 ft from the centre of the gate. 
The position of two other cross walls may be inferred in the follow- 
ing way. A little to the south of cross wall bb L there was a subter- 
ranean chamber or vault b'b\ c'c\ which attracted much notice when 
it was first discovered. Internally this vault measured 19 ft. 3 in. north 
and south, by 9 ft. 9 in. east and west. It was 7 ft. 2 in. deep. Its 
walls were 1 ft. 6 in. thick and were covered with a hard coating of 
plaster. The floor over the vault was carried across by four beams, 
the holes where the ends of the beams rested being clearly visible! 
The west wall of the vault (b\ c\) was built against the foundation 
wa of the first line of arches G x D x . The north face of the north 
wall of the vault b'b\ was 3 ft. 3 in. distant from the south face of 
the cross-wall 66^ The internal distance between the east wall of 
the vault (5V) and the curtain was 2 ft. 3 in. In this part of the 
curtain wall (6c) an iron grating was found, built up inside the brick 
work of the wall just below the level of the floor. It seems to have 
served no special purpose. The south wall of the vault cV, was 
coated with plaster on both sides. Its north face was plastered down 
to the level of the floor of the vault. Its south face was plastered down 
tea foot below the level of the floor of the chambers along the east cur- 
tain. This would seem to show that wall c'c\ was continued up above 
the floor level so as to form a cross wall ec, dividing up the space be- 
tween bb L and dd L , and, I believe, that this was so because there must 
surely have been a cross wall between bb x and dd L , and I do not see 
where else it could have been conveniently placed except above c'c', as cc, 
The north face of this wall will be distant 126 ft. from the centre of the 
east gate. 
There is somewhat similar evidence for the existence of another 
cross wall cwj north of bb v Inside the curtain wall (at ab) there was 
built another wall a’a\ 1 ft. 6 in. and 24 ft. long which was carried up 
to within a foot of the floor level of the range of chambers along the 
