In connection with the subject of telegraphy, and as an instance of the versatility of Dr. Siemens’s inventive powers, I may point out that in 1876 he brought out the pneumatic postal telegraph tube, by which, as is pretty generally known, written messages are blown or sucked through tubes on various metropolitan routes, instead of being transmitted electrically. About the same time, also, he constructed his ingenious bathometer, for ascertaining the depth of the sea at any given point, without the tedious operation of sounding; and some years previously he worked out his electrical thermometer or pyrometer, enabling the observer to read the temperature (whenever he desired) at any distant and inaccessible point, such as the top of a mountain, the bottom of the sea, the air between the layers of a cable, or the interior of a furnace. Probably the most prominent idea associated in the public mind with the name of Siemens is that of electric lighting, and perhaps electric tram and railroads. As I have more than once pointed out in this room, the dynamo-machine, by which mechanical energy is converted into that form of energy known as electricity (which may be used both for lighting and for the transmission of power), is derived from a principle discovered by Faraday in 1831. Sir William Siemens’ devotion to this, and the important practical consequences which he deduced from it, constitute another example of that mental characteristic to which I have already alluded. Faraday’s discovery, briefly described, was that when a bar magnet was suddenly inserted into a coil of wire, or when a wire was suddenly moved through a magnetic field, a momentary current of electricity was developed in the wire. Although this current is exceedingly small and brief, it is capable of unlimited multiplication by mechanical arrangements of a simple kind. One means for accomplishing this multiplication was the Siemens armature of 1857, which consisted, at first, of a piece of iron with wire wound round it longitudinally, not transversely, the whole to be rotated between the poles of a powerful magnet; in its present form it is one of the most powerful and perfect things of its kind, and the evolution of the Siemens armature, as we now have it, from the rudimentary type of a quarter of a century ago, has been characterised by Sir W. Thomson as one of the most beautiful products of inventive genius, and more like the growth of a flower than to almost anything else in the way of mechanism made by man.