80 REPORT OF THE SECRETARY. 



the more remarkable and important developments in physical and biological dis- 

 covery, as well as showing the general character of the operations of the Institution; 

 and this purpose has, during the greater part of its history, been carried out largely 

 by the publication of such papers as would possess an interest to all attracted by 

 scientific progress. 



In 1880 Secretary Baird, induced in part by the discontinuance of an annual sum- 

 mary of progress which for thirty years previous had been issued by well-known pri- 

 vate publishing firms, had prepared by competent collaborators a series of abstracts, 

 showing concisely the prominent features of recent scientific progress in astronomy, 

 geology, meteorology, physics, chemistry, mineralogy, botany, zoology, and anthro- 

 pology. This latter plan was contiuued, though not altogether satisfactorily, down 

 to and including the year 1888. 



In the report for 1889 a return was made to the earlier method of presenting a 

 miscellaneous selection of papers (some of them original) embracing a considerable 

 range of scientific investigation and discussion. 



So much trouble has been experienced in securing papers of the character desired 

 for the general appendix of the report that the Secretary has stated his ideas defi- 

 nitely in the following printed rules for the guidance of those who cooperate in 

 selecting the articles : 



RULES FOR THE SELECTION OF PAPERS FOIi THE GENERAL APPENDIX TO THE ANNUAL 



REPORT. 



So much difficulty has been found in obtaining the class of papers desired by the 

 Secretary for the appendix to his annual report that he takes this method of express- 

 ing his wishes to those gentlemen who are good enough to favor him with their 

 cooperation in making a selection. 



He asks that it may be remembered : 



1. That these papers have a purpose distinct from any others published by the 

 Institution. They are only occasionally original contributions lo science. They are 

 not for the professional reader only, or even chiefly, but they are addressed to that 

 large body of the public which has a general interest in scientific matters without 

 special knowledge. 



2. That while it is always a recommendation that they should have been written 

 by recognized authorities, yet this is of minor importance if the articles are sound 

 expositions of the subject. The essential thing is that they should be not only 

 sound and instructive, but timely and interesting to the nonprofessional reader, and. 

 in that good sense popular. If they are accompanied by illustrations all the better. 



3. As they are wanted to serve as a kind of survey of the Avhole field of the 

 sciences, both physical and biological, for the past year, it is as a rule impracticable 

 to print more than one on any particular subject. While the Secretary will be very 

 glad, then, to have any number suggested in English, French or German which will 

 meet these requirements, he will not expect as a rule to make use of more than one. 



4. The papers may be, in exceptional cases, as brief as 1.000 words. They should 

 rarely exceed 10,000 or 12,000. 



5. At the risk of needless iteration it is repeated that what is wanted is not for 

 the specialist, but interesting and popular expositions of what the specialist knows 

 to be sound and opportune. 



S. P. Langley, Secretary. 

 Washington, D. C, March, 1898. 



i. contributions to knowledge. 



One new memoir of the "Contributions," on Specific Heat Ratios, has been pub- 

 lished, and Secretary Langley's memoir on Internal Work of the Wind has been 

 reprinted in a small edition with some slight additions and changes. 



No. 1126. A Determination of the Ratio (Kappa) of the Specific Heats at Constant 

 Pressure and at Constant Volume for Air, Oxygen, Carbon-Dioxide, and Hydrogen. 

 By O. Lunimer and E. Pringsheini. City of Washington. Published by the Smith- 

 sonian Institution, 1898. 4°. V + 29 pp., with 1 plate and 3 text figures. (From 

 Smithsonian Contributions to Knowledge, Vol. XXIX.) 



This memoir is the result of a series of investigations by Drs. Lummer and Prings- 

 hime, aided by a grant from the Hodgkins fund. 



