PRESIDENT'S ADDRESS. Ixix. 



plans without the enemy's knowledge. It has probably 

 made much more difference in this respect than in its more 

 distinctly destructive work of dropping bombs, which has 

 not, perhaps, been so effective on the whole as had been 

 anticipated. One cannot but feel that many of these 

 wonderful inventions are very far from being a benefit to 

 the human race, and some of them are great evils, though 

 as soon as they exist, it is unfortunately impossible to ignore 

 them. Aeroplanes have much increased in stability, and 

 there are recent records of rates of 135 miles an hour, and of 

 ascents to an altitude of 5 miles. A gyroscopic motor car 

 with two wheels like a bicycle has been invented, and a trial 

 was lately made in London ; but the engine was not strong 

 enough to w r ork the gyroscope and also to drive the car at 

 more than 4 miles an hour. I am not aware that it has yet 

 been tried with a stronger engine. The quick turning of 

 corners may prove difficult. The optophone is an ingenious 

 instrument intended to render ordinary printed type into 

 sounds by means of a moving disc perforated with holes 

 through which the light is thrown on the printed page and 

 reflected on to a selenium bridge in connection with a 

 telephone, different sounds being caused according to the 

 intensity of the light. This is said to be sufficiently clear 

 to enable a blind person to read the printed page by hearing 

 the sounds which are produced, and, if successful, it will be 

 of great value to those thus afflicted. Other inventions 

 are a firedamp indicator, in which the presence of a minute 

 quantity of firedamp produces a musical note, and, secondly, 

 the application of the Hughes induction balance to military 

 surgery, when again a sound is produced by the presence of 

 metal. A monster locomotive engine has been built for 

 steep gradients on the Erie railroad, the wheel base being 90 

 feet in length and the weight of engine and tender 380 tons. 

 A cable is now laid between Sweden and Denmark, where the 

 width of The Sound is only 3 miles, to supply Denmark with 

 electric power, and is the first submarine cable laid for such 

 a purpose. It seems probable that electrolytic iron may 



