d of three equal parts,
lengthened toward the axles by narrow compartments, which can be
utilized for luggage or converted into lavatories, etc. Above is one
single compartment with a central passage, which is reached by
staircases at the end. All the vehicles of the same train are to be
united at this level by jointed platforms furnished with hand rails.
It is sufficient to point out the general disposition, without
entering into details which do not affect the system, and which must
vary for the different classes and according to the requirements of
the service.

[Illustration: M. ESTRADE'S HIGH SPEED LOCOMOTIVE.]

M. Nansouty draws a comparison between the diameters of the driving
wheels and cylinders of the principal locomotives now in use and those
of the Estrade engine as set forth in the following table. We only
give the figures for coupled engines:

TABLE II.

+--------------------+------------------+-----------+-------------+
| | Diameter of | Size of | |
| | driving wheels. | cylinder. | Position of |
| | ft. in. | in. in. | cylinder. |
+--------------------+------------------+-----------+-------------+
|Great Eastern | 7 0 | 18 x 24 | inside |
+--------------------+------------------+-----------+-------------+
|South-Eastern | 7 0 | 19 x 26 | " |
+--------------------+------------------+-----------+-------------+
|Glasgow and | | | |
|Southwestern | 6 1 | 18 x 26 | " |
+--------------------+------------------+-----------+-------------+
|Midland, 1884 | 7 0 | 19 x 26 | " |
+--------------------+------------------+-----------+-------------+
|North-Eastern | 7 0 | 171/2 x 24 | " |
+--------------------+------------------+-----------+-------------+
|London and | | | |
|North-Western | 6 6 | 17 x 24 | " |
+--------------------+------------------+-----------+-------------+
|Lancashire and | | | |
|Yorkshire | 6 0 | 171/2 x 26 | " |
+--------------------+------------------+-----------+-------------+
|North British | 6