Under the supervision of Mr Preece, the well-known electrician to the Post-office, an experiment of great interest has been recently conducted at Wimbledon, near London. The object of the experiment was to ascertain the best method of lighting streets by electricity, the lamps employed being the incandescent pattern advocated by Edison, Swan, and others. Some of the lamps were placed singly, others on poles twenty feet high, while at the same time the efficiency of different kinds of reflectors was tested. The cost is calculated to amount to one farthing per lamp per hour for each unit of light, valued at ten candles. Now, the cost of gas for a similar amount of light is one-fifth of a penny, so that the difference in expense between the two systems is not very great. On the other hand, the advantages of the electric light in the open air, where no question of impure products of combustion need come in, almost disappear; gas, therefore, still fulfils the required conditions. It is to be hoped that the new regulations for the prevention of collisions at sea, which have just been published, will have the effect of reducing those calamities, which have of late become fearfully familiar. The twenty-seven articles contained in these regulations refer to lights, sound-signals for fog, steering and sailing rules, precautions to be adopted, and special rules for squadrons and convoys. We may call particular attention to article nineteen, which indicates how one vessel can signal to another by a steam-whistle. Thus—one short blast to mean, ‘I am directing my course to starboard;’ two short blasts, ‘I am going to port;’ three to mean, ‘I am going full speed astern.’ Any one will readily remark how such signals could be added to almost indefinitely. Indeed, it is simply the method adopted in the army for flash-signalling with the heliograph, adapted to sound-signalling with the steam-whistle. In such a system, unfortunately, there are few, in moments of danger, who can keep their heads cool enough to avoid making perilous mistakes. It is somewhat like talking quietly when the house is on fire.