SCIENCE. 



[N. S. Vol. XVI. No. 414. 



aversion for everything that savored of 

 ostentation. Subsequently he refused re- 

 peatedly such honorary degrees as were 

 offered him, yielding only during the last 

 few years to the two institutions, Prince- 

 ton and Yale, with which his early associa- 

 tions were strongest. In 1858 he returned 

 to America with a German bride, and ac- 

 cepted an offer of the professorship of 

 chemistry and physics in the Troy Univer- 

 sitj', a denominational institution which 

 had recently been organized in the imme- 

 diate neighborhood of the better known 

 Rensselaer Polytechnic Institute. Here 

 Professor Rood remained five years. He 

 resigned in 1863, and during the following 

 year he accepted the chair of physics in 

 Columbia CoUege, which had just been 

 made vacant by the withdrawal of Pro- 

 fessor R. S. McCuUoch. For thirty-eight 

 years, including the best years of ma- 

 ture manhood, from thirty-three to nearly 

 seventy-two, his name has been widely 

 known in connection with this institution 

 as one of its scientific staff. Of his early 

 colleagues, Barnard, Joy, Egleston, New- 

 berry, Peck and Chandler, three of whom 

 organized the School of Mines, which is 

 now the school of applied science in Co- 

 lumbia University, all but one have now 

 passed away. 



As a physicist Professor Rood gave but 

 little attention to abstruse mathematical 

 analysis. He was essentially an experi- 

 mentalist, and one of great originality and 

 skill. His period of greatest activity pre- 

 ceded the present day of extreme special- 

 ization. Much of his work belonged to the 

 domain shared by the physicist, artist and 

 psychologist. As a yoting man in Europe 

 he had access to the best that was afforded 

 in such art centers as Munich, Dresden and 

 Berlin. He had a passionate love for art, 

 and the study of the triumphs of Rubens 

 and Titian in color was to him as en- 

 gaging as the more exact work of Fraun- 



hofer, ilaxwell and Helmholtz. At his 

 summer home in Stockbridge, Massachu- 

 setts, his vacations were devoted largely 

 to recreation with brush and pencil, and 

 many of his water-color sketches have 

 elicited admiration at the annual exhibi- 

 tions of the American Water Color Society 

 in New York. He had a weU-trained ear 

 for music, and in physics his fondness for 

 acoustics and optics was marked. As a 

 lecturer his style was singularly clear, and 

 his illustrations were well selected and 

 happy. A popular lecture on 'Mysteries 

 of the Voice and Ear,' delivered in 1873 

 before the Yale Scientific Club, was uni- 

 versally regarded as a model of its kind. 

 Tyndall had just finished a series of lec- 

 tures in America that aroused great public 

 interest and created a demand that was 

 well met by Morton, Mayer and Rood. 



Soon after beginning his duties in Troy 

 Professor Rood published in the American 

 Journal of Science an article 'On Adapt- 

 ing the Microscope as a Goniometer and 

 for Determining Index of Refraction.' 

 This indicated the choice he had already 

 made of experimental optics as a specialty. 

 It was soon followed by papers on 'Cir- 

 cular Polarization by Cooled Glasses,' 

 ' Contraction of the Muscles by Vibration, ' 

 'On Probable Means of Rendering Visible 

 the Circulation in the Eye, ' and a criticism 

 of 'A New Theory of Light' which had 

 just been propounded by an Englishman, 

 John Smith. His lifelong interest in 

 physiological optics became well developed 

 about this time, and he had an interested 

 co-worker in his colleague, Professor Edwin 

 Emerson. Among his papers on this sub- 

 ject was one 'On a Method of Producing 

 Stereographs by Hand' (1861) ; others 

 'Upon Some Experiments Connected with 

 Dove's Theory of Luster' (1861) ; 'On the 

 Relation between our Perceptions of Dis- 

 tance and Color' (1861) ; and 'On some 

 Stereoscopic Experiments' (1862). 



