necessary to train up a body of engine-drivers who should be capable of managing these new engines, for they required the exercise of a then unprecedented amount of care and skill. Finally, with the accomplishment of these two requisites to success, must simultaneously occur the enlightenment of the public, professional as well as non-professional, in regard to their advantages.

Thus it happens that it is only very recently that the screw has

attained its proper place as an instrument of propulsion, and has only now driven the paddle-wheel almost out of use, except in shoal water.

Now our large screw-steamers are of higher speed than any paddle-steamers on the ocean, sometimes crossing the Atlantic from New