APPENDIX. RECORD OF AURORAL PHENOMENA OBSERVED IN THE HIGHER NORTHERN LATITUDES. COMPILED BY PETER FORCE. INTRODUCTORY LETTER. PROFESSOR JOSEPH HENRY, Secretary Smithsonian Institution. SIR: In compliance with your request, I place in your hands the collection of observations on the Aurora Borealis, which was made in great part while I was engaged, during the evening hours of relaxation, for several years prior to 1851, in the examination of another, and, to me, at the time, a more interesting subject. In the course of this investigation I met with so many notices of the Aurora, that I thought it worth the time it would take, to gather such of them as came within my reach without leaving the path over which I was travelling; it also occurred to me that such a collection, covering so broad a surface, might be useful in any investigation of the phenomenon, in so far at least, as it would furnish the means of a ready reference to many of the observations recorded by careful and compe tent observers. The accompanying papers are my original notes, as they were made from time to time, from the later voyages, travels, and explorations in the northern regions, and particularly in the northern portions of North America. A list of the journals, &c., that I have gone over, which is added, will show how far my examination has extended. You will perceive that very few of the Auroral observations I have given were made south of the fiftieth degree of north latitude.1 North of that parallel they are quite full, though not entirely complete. Any omissions may, however, be easily supplied, as the name of the observer, the point of the first appearance and 1 In a work recently published by the State of New York, entitled "Results of a Series of Meteorological Observations made in Obedience to Instructions from the Regents of the University of Sundry Academies in the State of New York, from 1826 to 1850, inclusive, compiled by Franklin B. Hough, M.D., Albany, 1855," will be found a very full record of all auroras noticed in New York within the limits mentioned. I would also refer to various professed treatises on the subject, and especially to the volume on Auroras published in the Reports of the French "Commission Scientifique du Nord en Skandinavie, Laponie, &c." the direction of the Aurora, the time of observation, and the locality, by parallel and meridian, are stated in every instance where it was found possible to do so. I may venture to add that the observations here given, go far, as it appears to me, to establish the following points in regard to the Aurora Borealis : 1. That in the higher northern latitudes it frequently first appears to the castward, or to the westward, or to the southward of the observer, and hence is not strictly a north polar light. 2. That it is often at a low elevation, and sometimes near the surface of the earth, within the range of the vision of the observer. 3. That north of the 70th degree of north latitude it is less frequent and less brilliant than to the southward of that parallel. 4. That on and in the vicinity of the Atlantic Ocean and other open waters, it is most frequent and most brilliant. 5. That the season for its appearance is mostly between the autumnal and the vernal equinox. 6. That the time of its appearance is in most cases from six o'clock P. M. to midnight. WASHINGTON, May 1, 1856. PETER FORCE. |