186 



SCIENCE 



[Vol. LVI, No. 1442 



given the Maori name Huia, and was regarded 

 as the honorary chief of a Maori tribe. Queen 

 Victoria became his godmother. Favored by 

 circumstance, strong and handsome, he passed 

 through Eton and Cambridge University, with 

 every prospect of a brilliant career. But when 

 taking a holiday in the Tyrol in July, 1911, he 

 struck his head against a rock in diving, and 

 was so severely injured that he became para- 

 lyzed from the waist downward. An appar- 

 ently helpless invalid, he was condemned to 

 spend the rest of his life on a couch, able only 

 to move his head and arms. Many men, so 

 situated, would have given up all idea of useful 

 activities, lamenting a life of supposedly un- 

 avoidable idleness. Not so Mr. Onslow. Hav- 

 ing been much interested in biological subjects 

 when in college, he returned to Cambridge, 

 secured fihe necessary assistants, and ardently 

 devoted himself to biological research. Those 

 interested in genetics will remember his papers 

 on heredity in moths, based on breeding expe- 

 riments carried on in his laboratory. His 

 doubtless most important work, of 74 pages, 

 was "On a periodic structure in many insect 

 scales, and the cause of their iridescent 

 colours" (Philosophieal Transactions of the 

 Royal Society, July, 1921). In this elaborate 

 and fully illustrated paper the iridescent colors 

 of many insects of various orders are studied, 

 using all the modern refinements of micro- 

 scopic technique and the latest pertinent re- 

 searches in physics. All tihe drawings on the 

 three plates are by Mr. Onslow. A few years 

 ago Mr. Onslow was married to Miss Muriel 

 Wheldale, formerly a fellow of Newnham Col- 

 lege, well-known for researches on biochemistry 

 and especially for her book on the anthocyanin 

 pigments of plants. Marriage did not prevent 

 her from continuing her work at the university, 

 and so Onslow lived, as he wished to do, in the 

 atmosphere of the laboratories, closely in touch 

 with whatever was going on, himself an actor 

 in the great scientific drama of the day. When 

 I saw him in 1920 I was struck by the keenness 

 of his mind and the breadth of his interests. 

 His was a remarkable life, fruitful in many 

 ways, and ever worthy to be remembered. 



t. d. a. cockerell 

 University op Colorado 



SCIENTIFIC EVENTS 

 ILLUMINATING ENGINEERING NOMENCLA- 

 TURE AND I'^HOTOMETRIC STANDARDS 



The American Engineering Standards Com- 

 mittee announces that the Illuminating Engi- 

 neering Nomenclature and Photometric Stand- 

 ards of the Illuminating Engineering Society, 

 1918 edition, have been approved by the 

 American Engineering Standards Committee 

 as "American Standard," with the substitution 

 of six internationally agreed upon definitions 

 for certain ones of the 1918 rules. The defini- 

 tions which have been reworded are : luminous 

 flux, luminous intensity, illumination, candle, 

 lumen and lux. 



The special committee of the American En- 

 gineering Standards Committee which exam- 

 ined the proposal submitted by the Illuminating 

 Engineering Society and which recommended 

 approval of the nomenclature and photometiic 

 standards included representatives of the U. S. 

 Bureau of Standards, the American Gas Asso- 

 ciation, the American Physical Society, the 

 International Acetylene Association, the Op- 

 tical Society of America, the American Insti- 

 tute of Electrical Engineers, the Illuminating 

 Engineering Society and the National Electric 

 Light Association. 



The new tests to be substituted for existing 

 text in sections 3, 8, 9, 10, 12 and 13 of the 

 Nomenclature and Standards Rules of the 

 Illuminating Engineering Society of 1918 are 

 as follows : 



Section 3 : Luminous Flux is the rate of flow 

 of radiamt energy evaluated mth reference to 

 visual sensation. Although luminous flux must 

 strictly be defined as above, it may be regarded 

 for practical photometric purposes as an entity, 

 since the rate of flow is for such purposes inva- 

 riable. 



Section 8 : The Luminous Intensity of a point 

 source in any direction is the flux per unit solid 

 angle emitted by the source in that direction. 

 (The flux from any source of dimensions which 

 are negligibly small by comparison with the dis- 

 tance at which it is observed may be treated as 

 if it were emitted from a point.) 



Section 9: Illumination at any point of a sur- 

 face is the luminous flux density at that point, 

 or, when the illumination is uniform, the flux 

 per unit of intercepting area. 



