glass obtained from Vienna, very thick and warranted
to withstand the hardest blows. Along each side of the vessel there was
an observation platform or gallery on to which the exterior doors
opened, and each gallery was provided with a protecting railing.

The interior of the ship was divided into five separate compartments,
the rear one being the general living and sleeping room, having
observation windows so arranged as to command an outlook in all
directions. The next compartment was mainly a store-room, but, like all
the others, could be used for observation purposes; next to that was a
small compartment intended for a special purpose which will hereafter be
apparent; then another containing water storage, apparatus for
compressing or rarefying air, as well as machinery for producing the
latter chemically.

Lastly, right in the forepart of the vessel was M'Allister's special
sanctum, containing the driving, lighting, warming, and steering
machinery, but electric buttons and switches were also provided for
controlling these in every compartment, so that whichever one we
happened to be in we were prepared for all emergencies. Periscopes
capable of being turned in all directions also communicated with every
compartment, thus we could always see what might be around us.

All the machinery was either electric or magnetic, some of it being very
simple; other portions were extremely intricate, but nearly all was the
outcome of our joint inventions. Such parts as could not profitably be
made by ourselves had been carefully distributed between several firms
of founders and engineers, in order that none could have any means of
discovering the use to which they were intended to be put. The whole of
the shell of the vessel was double, with a packed space between the two
skins; and each door opened into a small lobby, having another door on
the farther side, to ensure that every part might be kept perfectly
air-tight when required.

By the time we had completed a thorough inspection of the vessel and its
machinery, and overhauled the stores to make sure that everything
requisite was on board, it had become nearly dark, so, moving a switch,
M'Allister swung open the great doors at the end of the shed. The vessel
was standing upon a low trolley having many wheels running on rails,
with a small electric motor beneath it, and, upon M'Allister moving the
trolley switch, the whole affair glided smoothly out into the open
field. I