[Illustration:  BROWN’S ELECTRIC SPEED REGULATOR.]

Mr. Brown’s system is based upon a new idea.  The apparatus (see figure) consists of two contacts connected by an electric circuit.  One of them, b, is fixed to the ship in such a way as to be constantly in the water, while the other, a, corresponds to the position above which the screw cannot rise without taking on a dangerous velocity.  In the normal situation of the ship, the electric circuit, c (in which circulates a current produced by a dynamo, d), is closed through the intermedium of the water, which establishes a connection between the two contacts.  When the contact, a, rises out of the water, the current is interrupted.  The electro, d, then frees its armature, f, and the latter is pulled back by a spring—­a motion that sets in action a small steam engine that closes the moderator valve.  When the contact, a, is again immersed, the electro, e, attracts its armature, and thus brings the moderator valve back to its normal position.  It is clear that the contact, a, must be insulated from the ship’s side.

Several contacts, a, might be advantageously arranged one above another, in order to close the moderator valve more or less, according to the extent of the screw’s rise or fall.

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MAGNETO-ELECTRIC CROSSING SIGNAL.

We illustrate to-day a new application of electricity to railroad crossing signaling which the Pennsylvania Steel Company, of Steelton, Pa., has just perfected.  By its operation an isolated highway crossing in the woods or any lonely place can be made perfectly safe, and that, too, without the expense of gates and a man to work them or of a flagman.  It is surely a great improvement over the old methods, and it is likely to have a large sale.  In addition to considerations of safety, possible saving in salaries to railroad companies by its use will be great.  This device is more reliable than a human being, and can make any crossing safe to which it is applied.  Its operation is described as follows: 

[Illustration:  FIG. 2.—­MAGNETO-ELECTRIC CROSSING SIGNAL]

The illustration shows the device as used on a single track railroad, where it is so arranged as to be operated only by trains approaching the crossing (i.e., in the form illustrated, from the right).  A similar box on the other side of the crossing is used for trains approaching in the other direction.  Two plates connected by a link, and pivoted, are placed alongside of one rail, close enough to it to be depressed by the treads of the wheels.  By another link, one of the plates called the rock plate (the one to the right) is connected to a rock shaft which extends through a strong bearing into the heavy iron case or box shown, at a suitable distance from the rail, within which an electric generator is placed; the whole being mounted and secured upon the ends of two long ties framed to receive it.