January 20, 192 1] 



NATURE 



681 



Calendar of Scientific Pioneers. 



January 20, 1907. Agnes Mary Gierke died.— 

 Widely known for her astronomical writings, Miss 

 ("lerke, like Mary Somerville, Caroline Herschel, Ann 

 Sheepshanks, and Lady Huggins, was an honorary 

 member of the Royal .Astronomical Society. 



January 21, 1892. John Couch Adams died.— Few 

 ■icientitic achievements have aroused more interest or 

 more controversy than the discovery of Nepturve, and 

 the careers of few astronomers have opened so bril- 

 liantly as that of Adams, who simultaneously with 

 f-everrier worked out the calculations demonstrating 

 the existence of this planet. After working at the 

 problem for two years Adams in September, 1845, 

 communicated his results to Challis, and in October 

 to .Airy. Leverrier's papers were published shortly 

 afterwards, and Neptune was first seen by Galle at 

 Berlin on September 23, 1846. Adams, who was born 

 in Cornwall on June 5, 1819, became Lowndean pro- 

 fessor in the University of Cambridge in 1858, and 

 in 1861 succeeded Challis as director of Cambridge 

 Observatory. 



January 22, 1799. Horace Benedict de Saussure 

 died. — Saussure was the first great explorer of the 

 .Alps. A naturalist and a physicist, be has been called 

 " the founder of experimental geology," and he is said 

 to have been the first to place meteorology on a 

 reasonable basis. 



January 22, 1840. Johann Friedrich Blumenbach 



died. — For more than fifty years Blumenbach held the 



hair of anatomy at Gottingen, and wrote works on 



physiology, anatomy, embryology, and ethnology 



which became European text-books. 



January 22, 1867. Sir William Snow Harris died.— 

 A prominent worker in electricity, Harris bv his now 

 form of lightning conductor added greatly to the 

 safety of ships at sea. 



January 22, 1900. David Edward Hughes died.— 

 Son of a bootmaker who emigrated to .America, 

 Hughes in 1855 patented his type-printing telegraph, 

 and in 1857 came to England. In 1878 he patented 

 his microphone. Recognised as one of the greatest 

 scientific inventors of the age. he amassed a fortune 

 of nearly half a million sterling, which was given 

 mainly to London hospitals and scientific societies. 

 January 24, 1877. Johann Chrittian Poggendorf 

 W. — Poggendorf was for fifty years editor of the 

 ^.^nnoien der Phy.tik und Chemie. 



January 24, 1914. Sir David Qill died.— Astro- 

 nier-Royal at the Cape of Good Hope, dill was one 

 the best known astronomers of his day. He is 

 ecially remembered for his great geodetical opera- 

 Bns, his determination of the solar parallax, and his 

 (loneering work in connection with the photographic 

 fiurvey of the heavens. 



January 26, 1631. Henry Briggs died.— On the 



! foundation of Gresham College, London, Briggs was 



appointed to the chair of geometry, the first of its 



kind in England. He was also the first to hold the 



Savilian chair of geometry at Oxford. 



January 26, 1823. Edward Jenner died.- After 

 ^twenty years' exprrimenling, jenner on May 14, 171)6. 

 ; made his first vaccination. Three years later seventy 

 London doctors declare<l their confidence in his dis- 

 covrrv, which was soon promulgated throughout the 

 world. Parliament acknowledged the countr\-'s in- 

 debtedness to him by voting him sums totalling 

 30,000!. 



January 26, 1S9S. Arthur Oayley died.- Senior 

 wrangler in 1842, Cayley for many years was a law 

 <i)nvev.nnrer, but In 1863 became first Sadlerian pro- 

 of mathematics at Cambridge. E. C. S. 



NO. 2673, VOL. 106] 



Societies and Academies. 

 London. 

 Aristotelian Society, January 3. — The Very Rev. Dean 

 W. R. Inge, president, in the chair. — C' A. Ricbard>. 

 son : The new materialism. The new materialism 

 takes the form of a denial of anything corresponding 

 to the idea of "mind" or "subject." Unlike the old 

 doctrine, it does not affirm the reality of atoms ; its 

 ultimate stuff is sense-material. It reduces the sub- 

 ject of experience to a series of sense-data, and the 

 sense-data are conceived as ontologically independent 

 of the subject. Against this it was argued that the 

 subject of experience is a real metaphysical existence. 

 Experience consists in spiritual activity, and one type 

 of this activity is sense-experience. The content, 

 sense-data, is the particular form the activity assumes, 

 and the form is determined by the interaction of 

 individual subjects. The most pressing philosophical 

 need of the day is to come to an agreement on this 

 point. Until we are agreed as to whether there exists 

 the subject or mind there must be disagreement on 

 the fundamental matter of philosophy, namely, the 

 entities in terms of which theories may be formulated. 

 Without a common platform philosophy will be left 

 behind, a curious relic, by the intuitive wisdom of the 

 vast mass of humanity. 



DUBUN. 



Royal Dnblln Society, December 21.— Dr. F. E. 

 Hackett in the chair.— J. J. DowUng and D. Donnelly : 

 The measurement of very short intervals of time by 

 the condenser-charging method. An investigation of 

 the degree of accuracy obtainable in the measure- 

 ment of short time intervals by a method in which 

 the time interval is determined by observing the 

 charge taken up by a condenser connected to a source 

 of steady electromotive force through a known resist- 

 ance during the interval in question. It was found 

 possible to measure intervals of thirty millionths of a 

 second with an accuracy of one millionth of a second. 

 — J. J. DowUog and J. T. Harris: An apparatus is 

 described whereby a spark-gap, included in the 

 secondary circuit of a high-tension transformer, is 

 rendered conducting during one-half of each cycle, 

 thus permitting a current to flow in one direction 

 only. The primary current energises an electro- 

 magnet which .sets into vibration the diaphragm of 

 a Kdnig manometric flame, situated in the spark-gap. 

 .A subsidiary winding allows the magnet to be polaristnl 

 by a steady current so as to cut out each alternate 

 flame oscillation. Various tests of the apparatus are 

 described which indicate that very complete rectifica- 

 tion is obtainable. — J. J. Dowling : A sensitive valve 

 method for measuring capacities, with some important 

 applications. A steady source of alternating e.m.f. 

 is connected to a circuit consisting of a high resist- 

 ance in series with a condenser. Trie drop otpotential 

 across the resistance is proportional to the capacity 

 of the condenser. The filament and grid of a three- 

 electrode valve respectively are connected to the ends 

 of the resistance, and variations of the capacity of the 

 condenser thus bring about corresponding variations 

 in the plate current. The greater part of this is 

 balanced by an opposed steady current derived from 

 a battery connectea through an adjustable resistance 

 to the galvanometer terminals. Using a galvano- 

 meter of high sensitivity, very small variations can 

 be detected. The application of this principle to the 

 construction of an ultra-micrometer and of a micro, 

 pressure gauge arc described. Displacements of the 

 order of 10- ' cm. are easily measurable. Further 

 work is in progress. 



