April 15, 1922] 



NA TURE 



485 



.may be one of many and will inevitably attain its 



iree score and ten ; terminating in labour and sorrow. 



lut there must come a leju venation, and the re- 



ivenation, possibly, may one day be pondered by 



»ther Minds than ours. Remember that after some 



ten thousand millions of years there still survives 

 50 per cent, of the heat-generating elements, and the 

 effect of their diminution is only to lengthen out the 

 recurring geological ages. Our planetary companions 

 may be in various stages of such cyclical changes. 



Recovery of Hughes's Original Microphones and Other Instruments of Historic Interest. 



By A. A. Campbell Swinton, F.R.S. 



FROM the perusal of David Hughes's note-books 

 recently bequeathed to the British Museum by 

 [rs. Hughes, and sent to me for examination by the 

 deeper of the Manuscripts (see Nature, March 9, 1922, 

 ?P- 3i5"3i6), it became obvious to me that Hughes must 

 It one time have possessed numerous original instru- 

 lents, mostly constructed with his own hands, 

 laving been informed that the note-books had been 

 scued from " an incredible accumulation of useless 

 imber," it occurred to me to try to locate this 

 lumber " if still existent, and to see whether it- 

 )mprised any of the instruments. To make a long 

 story short, a room in a furniture depository not far 

 from the Tottenham Court Road was found to be 

 illed with Hughes's personal effects, which had been 

 Stored there since his death in 1900, when Mrs. Hughes 

 jtumed to America. Having interested Col. H. G. 

 ^yons, F.R.S. , Director of the Science Museum, in the 

 itter, the effects were carefully examined, when not 

 )nly were there discovered eight more note-books — one 

 containing an illustrated account of Hughes's inven- 

 tion of the microphone — but also numerous instruments. 

 These comprise a number of microphones, of which 

 several are different-sized instruments of the well-known 

 pivoted-lever type. Others consist of pointed carbon 

 pencils, loosely held at their ends between fixed carbon 

 sockets, the whole being mounted on sounding- 

 boards, which in one case takes the form of an in- 

 verted Japanese ash-tray. Several more consist of 

 carbon pencils suspended pendulum-wise* by paper 

 strips, so as to bridge other carbon pencils mounted 

 on vertical sounding-boards, while others, again, consist 



of glass tubes containing either carbon blocks held 

 together by a light spiral spring, or carbon granules. 

 Finally, among the microphones, there is the one 

 consisting of three French nails that has served to 

 illustrate many a text -book. 



In addition, there is an induction balance, probably 

 the first one that Hughes made, together with the 

 actual instruments with which he practised wireless 

 telegraphy in 1879. They are all readily identified 

 from the illustrated descriptions in the note-books, 

 and include the clockwork with which currents from a 

 single-cell battery, connected to one of the coils of 

 the induction balance, were interrupted so as to trans- 

 mit wireless signals. There are also two Bell tele- 

 phones, evidently made by Hughes himself, together 

 with two more which he says were made for him by 

 Sax, which he used for wireless reception in con- 

 nection with a water-tight pocket battery, and a special 

 microphone that seems to have acted as a self- 

 decohering coherer. This latter is contained in a glass 

 bottle, the loose contact being made between a steel 

 needle and a wire loop, which latter Hughes says 

 he made more sensitive by coating it with soot from 

 the flame of a spirit lamp. 



With these simple pieces of home-made apparatus 

 Hughes not only prepared the way for the modern 

 telephone transmitter, but also transmitted and 

 received wireless signals over distances up to 300 

 yards no less than 43 years ago. 



All these instruments have been made over to the 

 Science Museum, South Kensington, by Mrs. Hughes's 

 trustees, and are now on view in Room No. 10. 



Obit 



WE learn from the British Medical Journal that 

 Dr. Harris Graham died at Beirut, Syria, on 

 February 27. Dr. Graham, who was in his sixtieth year, 

 was of Canadian birth and was educated at Toronto and 

 -Michigan Universities. Going to Turkey as a mission- 

 ary he served four years at Aintab Medical College. 

 On its closure, he was called to Beirut and joined the 

 American University there in 1889. During various 

 leaves of absence he worked in Berlin and Vienna, 

 and advanced evidence that a Culex mosquito is the 

 carrier of dengue fever. He had an extensive practice 

 and spoke all the principal languages of the Levant. 

 Dr. Graham will be much missed, for he was an energetic 

 and inspiring teacher and a physician of great acumen. 



The Chemiker Zeitung of March 25 announces the 

 death, at the age of eighty-four years, of Prof. A. 

 Naumann. Prof. Naumann was one of the first 

 workers in the field of what is now called physical 



NO. 2737, VOL. 109] 



uary. 



chemistry. His researches on dissociation, thermo- 

 chemistry-, and mass action, and his text -book had 

 great influence on the science ; his name is prominent 

 in all the earlier work in this field. 



The death is announced, at the age of fifty-one years, 

 of Dr. George Vincent Wendell, who had occupied a 

 chair of physics at Columbia University since 1910. 

 From 1892 to 1907 he held various posts at the Massa- 

 chusetts Institute of Technology, and from 1907 to' 

 1910 he was professor of physics and head of the 

 department at the Stevens Institute of Technology, 

 New Jersey. 



We deeply regret to record the death on April 9, 

 at seventy-seven years of age, of Sir Patrick Manson, 

 G.C.M.G., F.R.S., whose pioneer work on tropical 

 diseases opened up fields of research of profound 

 significance both to science and civilisation. 



