The materials most suited for this new style of vessel will be iron and steel such as generally used in the construction of canal and river vessels. The new ship can be moved by any motor or driving implement, nor could there technically a great difficulty be found for making the boilers move on a quadrant-like rail base in the shape of a circle segment's quarter, or for building a double screw steamer by combining two single screw propellers. May be a ship owner is willing to submit the innovations to an attempt, so much the more as there is running no great risk by doing so; for in case the ships should not answer the expectations, both separable as well as joinable, they can be used like single ships, without any further alteration being made, except as to the loading gaps. The above invention is covered by United States patent No. 435,107. Any further information may be had by addressing M. v. Szabel, ix Bezirk, Beethovengasse 10, Wien, Austria. * * * * * WELDON'S RANGE FINDER. Colonel Weldon has recently considerably modified and improved his ingenious range finder, and we illustrate herewith from _Engineering_ the form in which it is now manufactured. It consists of a metal box, the lid of which is shown open in the engraving, and on this lid are fitted three prisms which are the essential constituents of the instrument. When the lid is closed, these, with the compass and level, also attached to the lid, lie inside the metal box, and are thus thoroughly protected. The upper prism marked 1 is a right-angled one and is mounted with the right angle outward; looking into the left-hand corner of this prism one will see in it, by double reflection, objects lying on one's right hand. Below this is a second prism with a principal angle of 88 deg. 51 min. 15 sec., and below this a third with a principal angle of 74 deg. 53 min. 15 sec.