THE PROGRESS OF SCIENCE. 



377 



THE PROGRESS OF SCIENCE 



SAMUEL PIERPONT LAXGLEY 



In the death of Dr. S. P. Langley, 

 secretary of the Smithsonian Institu- 

 tion, America loses one of its most 

 eminent men of science. Langley was 

 born in Roxbury, Mass., on August 22, 

 1834, descended from long lines of New 

 England ancestry. As a boy he was 

 interested in astronomy, radiant energy 

 and mechanical flight, and with his 

 brother, now Professor John W. Lang- 

 ley of the Case School of Applied Sci- 

 ence, he constructed telescopes. He 

 did not enjoy or suffer a college educa- 

 tion, but practised civil engineering 

 and architecture, until, at the age of 

 thirty-one, he became assistant in the 

 Harvard Observatory. In 1866 he went 

 to the U. S. Naval Academy as assist- I 

 ant professor of mathematics, and the 

 following year was made director of 

 the Allegheny Observatory and pro- 

 fessor of astronomy and physics in the 

 Western University of Pennsylvania. 

 In 1887 he was appointed assistant 

 secretary of the Smithsonian Institu- 

 tion and succeeded to the secretaryship 

 on the death of Baird the same year. 

 This was then, as it is perhaps still, 

 the most responsible position and the 

 highest honor that can be conferred in 

 this country on a man of science. 



Langley made his first published con- 

 tribution to science at the age of thirty- 

 five, it being a report on the total 

 eclipse of August 7, 1869, observed in 

 Kentucky. In the following year he 

 again observed a solar eclipse, making 

 observations on the coronal rays, and 

 this was followed by his important re- 

 searches on the solar photosphere. His 

 work on the radiant energy of the sun 

 resulted in and was promoted by the 

 invention of the bolometer, an instru- 

 ment which lias been perfected to mea- 



perature. This is accomplished by 

 changes of electrical resistance due to 

 heat and detected by a galvanometer, 

 whose fluctuations may be photo- 

 graphed. Some of Langley's most im- 

 portant observations were obtained in 

 1881 on Mount Whitney at an eleva- 

 tion of 14,000 feet, and they have been 

 continued to the present time in the 

 Astrophysical Observatory, which was 

 in 1891 established in connection with 

 the Smithsonian Institution. Probably 

 Langley's greatest work is connected 

 with the heat of the sun and the infra- 

 red rays of the spectrum, but perhaps 

 his researches on aerodynamics are 

 equally well known. His theoretical 

 and experimental contributions to this 

 | subject are of fundamental importance, 

 in no wise lessened by the fact that he 

 was unable to solve the practical prob- 

 lem of aerial flight. 



Langley died from a stroke of paral- 

 ysis on February 27. A sketch of his 

 life by Dr. E. S. Holden with a por- 

 trait was published in Volume XXVII. 

 of this journal. The frontispiece to 

 the present issue shows Dr. Langley in 

 the robes in which he received the 

 D.C.L, degree from Oxford University. 

 The regents of the Smithsonian In- 

 stitution have passed the following 

 memorial resolution : 



sure a millionth of a degree of tem- 



Hesolvecl. That the board of regents of the 

 Smithsonian Institution express their profound 

 sorrow at the death, on February 27, 1906, of 

 Samuel Pierpont Langley, Secretary of the In- 

 stitution since 1887, and tender to the relatives 

 <>f Mr. Langley their sincere sympathy in their 

 bereavement. 



That in the death of Mr. Langley this Insti- 

 tution has lost a distinguished, efficient and 

 faithful executive officer, under whose admin- 

 istration the international influence of the 

 parent institution has been greatly increased, 

 and by whose personal efforts two important 

 branches of work have been added to its care 

 — the National Zoological Park and the Astro- 

 physical Observatory. 



