190 



SCIENCE 



[N. S. Vol. XLIII. No. 1102 



transcontinental telephone line is 3,400 

 miles in length and transmits speech with- 

 out distortion. The chief factors that have 

 contributed to this result are the Bell re- 

 ceiver, the microphone, the coils for pre- 

 venting voice distortion, and finally the in- 

 vention of the thermionic amplifier. 



The twenty-fifth day of January of this 

 year marks the beginning of transconti- 

 nental telephony by wire and September 29 

 that of transcontinental telephony without 

 wires, both great achievements having been 

 accomplished in our own country and since 

 our last annual meeting. 



The experimental proof that the con- 

 denser discharge is oscillatory and Max- 

 well's (1831-1879) theory of electromag- 

 netic waves led Hertz (1857-1894) to devise 

 the apparatus which demonstrated the 

 existence of such waves. The value of these 

 purely scientific efforts is seen in the result. 

 It was found that connecting one end of 

 the vibrating system to the earth and the 

 employment of long antennse improved the 

 sending power of the transmitter; and the 

 development of detectors improved the re- 

 ceiving apparatus. We have then, as appli- 

 cations, the wireless telegraph which is 

 rendering such unusual service ; and finally, 

 with the development of the thermionic 

 amplifier, already mentioned, the wireless 

 telephone which has so recently enabled 

 the human voice to travel across our conti- 

 nent and beyond to Honolulu, a distance 

 of 4,850 miles. 



A modest-looking little bulb containing 

 a stream of almost inertialess particles 

 known as the thermionic current would 

 hardly have been suspected of being able to 

 bring about, as it has, so important a step 

 in the development of long-distance tel- 

 ephony of both kinds. By means of this 

 little instrument, or rather many of them, 

 the energy of the original telephonic cur- 

 rent can be increased many billion times. 



which is then transformed, in part, into 

 ether tremors and sent in all directions 

 across oceans and continents and there 

 transformed again, reproducing the orig- 

 inal speech without distortion. Our sense 

 of appreciation seems to have been hard- 

 ened by many and great successes. "We 

 seem to be stunned, unable to comprehend 

 fully the significance and the greatness of 

 such a marvelous achievement. 



Apparatus has been devised for the 

 counting of both the alpha and the beta 

 particles, and the existence of atoms has 

 been demonstrated beyond question. The 

 simplicity of the apparatus devised by 

 C. T. R. Wilson for making visible the 

 paths of the alpha and the beta particles, 

 atoms and the minute pieces of atoms, 

 makes us wonder whether anything is im- 

 possible, providing we have the genius to 

 devise the proper instruments. 



Radioactive substances would be explod- 

 ing with stupendous violence, and their 

 quivering atoms be sending ether pulses 

 into space, a whole world of great activity 

 about us, and we should be in complete 

 ignorance of it, were it not for the electro- 

 scope and the photographic plate. 



As was intimated at the beginning, this 

 partial summary has been presented mainly 

 for the purpose of illustrating the extent 

 to which the development of instruments 

 has been a contributing factor in scientific 

 progress. It is to be noted that in many 

 eases advancement can proceed to a cer- 

 tain point and then must necessarily stop, 

 no further significant progress being pos- 

 sible until some required instrument of re- 

 search is perfected or an entirely new one 

 devised. It is often more profitable to de- 

 vote time to developing instruments than to 

 the continuing of investigations whose re- 

 sults become obsolete as soon as the instru- 

 ments employed are improved. The pains- 

 taking observations of Angstrom, notwith- 



