252 ANNUAL OF SCIENTIFIC DISCOVERY. 



parts of the body, sensible differences have been observed, the shock applied 

 to the thumb being one-thirtieth of a second behind that applied to the 

 face ; and this difference pertains to the transmission and not to the action 

 of the brain, and hence enables us to eliminate the latter in the experiments. 

 In this way it has been found by M. Helmholtz, by whom these experiments 

 have been made with the most care, 



1. That sensations are transmitted to the brain at a rapidity of about 

 ISO feet per second, or at one-fifth the rate of sound ; and this is nearly the 

 same in all individuals. 



2. The brain requires one-tenth of a second to transmit its orders to the 

 nerves which preside over voluntary motion ; but this amount varies much 

 in different individuals, and in the same individual at different times, accord- 

 ing to the disposition or the condition at the time, and is more regular, the 

 more sustained the attention. 



3. The time required to transmit an order to the muscles by the motor 

 nerves, is nearly the same as that required by the nerves of sensation to pass 

 a sensation ; moreover it passes nearly one-hundredth of a second before the 

 muscles are put in motion. 



4. The whole operation requires one and a quarter to two tenths of a 

 second. 



Consequently when we speak of an active, ardent mind, or of one that is 

 slow, cold or apathetic, it is not a mere figure of rhetoric. M. Ule, Revue 

 Suisse. 



ON THE ESTABLISHMENT OF UNIFORM TIME BY MEANS OF THE TELE- 



GEAPH. 



Mr. J. J. Murphy, at the British Association, communicated a paper con- 

 taining a proposal for the establishment of a uniform reckoning of time over 

 the world in connection with the telegraph. The paper stated that the 

 period, in all probability, was not remote when the telegraph would effect 

 an almost instantaneous communication between parts of the world which 

 are separated by an extensive arc of longitude,, and differ in their solar 

 time by several hours. The system which had been introduced all over 

 Great Britain of keeping Greenwich time everywhere, could not be applied 

 over extensive arcs of longitude. A difference of half an hour between 

 solar time and clock time at any place was no inconvenience, but a dif- 

 ference of six hours would be much too great. It would be necessary for 

 distant places to continue to keep their local solar time ; but in order to 

 time the receipt and despatch by telegraphic messages it would be necessary 

 cither to reduce the time of one place to that of any other with which it 

 might communicate, or to adopt a uniform reckoning of time for all. "We 

 have to propose a simple and self-acting method of meeting ths require- 

 ments of the case. Let every telegraph station that communicated with 

 distant stations be furnished with a clock, similar in other respects to a 

 common clock, but provided with a double circle of figures on the dial, 

 the inner circle being fixed as in a common clock, but the outer one 

 capable of being moved round. Let some one meridian, say that of 



