270 ELECTRIC LIGHTING. 



Application to the Arts of War. The extreme in- 

 tensity of the electric light, and the ease with which it can 

 at will be made to instantly appear and disappear at a dis- 

 tance, render it capable of important applications in military 

 operations, either for signals, or as a means of illuminating at 

 night a distant point to be observed, or to light up the work 

 of the assailants in sieges. Martin de Brettes published, 

 twenty years ago, an interesting paper on this subject, and 

 this we have reproduced in the second edition of our Expose 

 des applications deT Electricity tome III., page 258. We have 

 here space for only a few extracts : 



" Signals in the field or at a siege," says Martin de Brettes, 

 " are chiefly intended for the transmission of orders or urgent 

 despatches. It is therefore clear that the best system of lumi- 

 nous signals is that in which the light is most simply produced, 

 is seen from the greatest distance, and has the greatest regula- 

 rity in the appearance of the lights combined to produce the 

 signs required in a telegraphic correspondence. 



"As to the property possessed by the electric light of being 

 seen at a considerable distance, its superiority for a good system 

 of signals cannot be disputed. Nevertheless, rockets may in 

 general, under ordinary circumstances, be advantageously em- 

 ployed on account of their simplicity, the ease with which they 

 can be carried about and used. But when a powerful permanent 

 luminous signal is required, the electric light will be of great 

 help, and may prevent the use of a captive balloon in the field. 



" Again, circumstances occur in war in which an illumination 

 of a longer or shorter duration is required ; for instance : 



" To reconnoitre a fortification, the besieger requires a mo- 

 mentary light sufficient for his purpose, and not so prolonged as 

 to attract the attention of the besieged. 



" To direct the fire of a battery on a given point, that point 

 must be lighted up long enough to allow a good aim to be taken. 



"In order not to be taken by surprise by the opening of 

 trenches, the besieged should continuously light up the ground 

 where that operation is likely to be executed. 



" The lighting up of a battle-field or of a breach a': the time 

 of the assault, requires also an illumination of an indefinite 

 duration. 



