The crank arms stand at angles to each other, so that the crank shafts are turned in opposite directions, and the position of the link is such that it can be readily changed by the reversing lever to simultaneously reverse the motion of the crank shafts.  On the crank shafts are also formed two other crank arms pivotally connected by opposite pitmen with a slide mounted in vertical guideways, supported on a frame erected on the base, the motion of the crank shafts causing the vertical sliding motion of the slide traveling loosely in the guideways, and thus serving as a governor, as, in case one of the propellers becomes disabled, the power of the shaft carrying the disabled propeller is directly transferred to the other shaft through the crank arms, pitmen, and slide, and the other propeller is caused to do all the work.  All the parts of the engine are within easy reach of the engineer, and there are so few working parts in motion that the friction is reduced to a minimum.

It is said that the plan of construction and the operation of this engine have been carefully observed by practical engineers, and that, considering the dimensions of the boat, her speed, the smallness of the power, the ease with which she passes the centers, the absence of vibration while running, and the very few working parts in motion, the engine is a notable success.  She can be run at a very high velocity without injury or risk, and is designed to be very economical in cost and in weight and space.  This engine has been recently patented in the United States and foreign countries by Mr. James A. Clarke, of New Westminster.

* * * * *

IMPROVEMENTS IN THE CONSTRUCTION OF RIVER AND CANAL BARGES.

By M. RITTER (KNIGHT) VON SZABEL, late Austrian Naval Officer, of Vienna.

This innovation consists essentially in an arrangement by which two distinct vessels, on being revolved round their longitudinal axis to an angle of 90 deg., can be combined into one single duplex vessel, or, to put it in different words, a larger vessel is arranged so that it can be parted into two halves (called “semi-barges"), which can be used and navigated with equal facility as two distinct vessels, as if combined into one.  By the combination of the two semi-barges into one duplex barge the draught of the vessel is nearly doubled, the ratio existing between the draught of a loaded semi-vessel and the equally loaded duplex vessels being 5:8 (up to 8.5)

The advantage of the invention consists: 

    1.  In this difference of draught.

    2.  In the smaller width of the semi-vessel as compared with
    the duplex vessel.

    3.  In the fact that the combination and separation of the
    vessels can be effected, without the least disturbance of the
    cargo, in a minimum of time.

It facilitates the utilization, to the highest possible extent, of the varying conditions and dimensions of canal locks and rivers.