3/4 | 196 | . . |
| 19-1/4 | 215 | 11 | 233 | . . |
| 36-1/2 | 588 | 17 | . . | 693 |
+-----------+----------+----------+----------+----------+

The remarkable shortness of these stops is the more evident when they
are compared with the best results obtained in 1886, as shown in Table
II.

TABLE II.--_Stops of a Train of Fifty Empty Cars, 1886--Automatic
Air-Brakes._

+-----------+----------+----------+---------------------+
| Speed in | Distance | Time in | Equivalent Distance |
| Miles. | in Feet. | Seconds. | at 20 m. and 40 m. |
+-----------+----------+----------+----------+----------+
| 23.5 | 424 | 17-1/2 | 307 | . . |
| 20.3 | 354 | 16 | 340 | . . |
| 40 | 922 | 22-1/2 | . . | 922 |
| 40 | 927 | 22-3/4 | . . | 927 |
+-----------+----------+----------+----------+----------+

The time that elapsed between the application of the brakes on the
engine and on the fiftieth vehicle was almost twice as great in 1886
as in 1887, being in the latter tests only five to six seconds, and in
1887 the stops were made in less than two-thirds the distance required
in 1886. Still, violent shocks were caused by the rear vehicles
running against those in front, before the brakes on the former were
applied with sufficient force to hold them, and these shocks were so
severe as to make the use of the brakes in practice impossible on long
trains. When the triple-valves were actuated electrically, however,
the stops were still further improved, as shown in Table III.

Table III.--_Stops of a Train of Fifty Empty Cars--Electric
Application of Air-Brakes._

+-----------+----------+----------+---------------------+
| Speed in | Distance | Time in | Equivalent Distance |
| Miles. | in Feet. | Seconds. | at 20 m. and 40 m. |
+-----------+----------+----------+----------+----------+
| 21-1/2 | 160 | 7 | 139 | . . |
| 23 | 183 | 8 | 138 | . . |
| 38 | 475 | 14-1/2 | . . | 519 |
| 36-1/2 | 460 | 14 | . . | 545 |
+-----------+----------+----------+----------+----------+

Although the same levers, shoes, rods and other connexions were used,
there were