loon observations at the Spitsbergen base will be given the fliers for the regions which they propose to explore. Little information as to upper air conditions in the Arctic regions is at present available. The series of balloon observations that Mr. Haines will make should therefore be of special value. The bureau will thus benefit in two ways: First, in the opportunity to furnish a very specialized type of service; and second, in obtaining data of unusual interest. The stay at Spitsbergen is expected to be of about one month's duration. Adapted from U. S. Dept. of Agriculture "Official Record," April 7, 1926. The Amundsen-Ellsworth Polar Expedition The Weather Bureau of the Department of Agriculture has co-operated with the Meteorological Institute of Norway in supplying a special service of radio weather reports for the benefit of the AmundsenEllsworth Polar Expedition during April and May of this year. The explorers purpose making an airship flight from Spitzbergen to the North Pole and return, and the Norwegian Institute is to supply meteorological information by radio to the expedition's vessel to be transmitted in turn to the explorers during their flight. The United States Weather Bureau during the months of April and May is making a number of additions to its daily bulletin of observations transmitted by radio to Europe, with a special view to the requirements of this expedition, and is also transmitting from the radio station at Cordova, Alaska, a special daily bulletin containing reports from several stations in Alaska for some days during the actual flight. - Adapted from U. S. Dept. of Agriculture Clip Sheet. Arctic Sunburn The aviators who will explore the Arctic this spring and summer must look out for sunburn. Perhaps you imagine sunburn is confined to hot days in warmer regions. Not at all! Near the pole, although the sun is low, it is constantly above the horizon, giving a length of exposure never experienced in lower latitudes. In addition to this, flights are likely to be made in good weather when the air is clear and dry, affording ready passage to the short wave-length ultraviolet rays which cause the burning. Flyers are always more exposed than people on the ground, for they have left below them the most absorbent portion of the atmosphere. Summer is the cloudiest season, with the sky eight or nine-tenths covered on the average in some parts of the Arctic, and fog on 10 to 20 days a month. In winter it is but half as cloudy, and fog is nearly absent. Clouds and fog, however, in the Arctic are seldom as dense and thick as they may become in warmer regions where a larger percentage of the air is water vapor. The aviator may expect snow in any month, but rain falls usually only from May to September. The precipitation is very light, averaging about 3 millimeters per month. It has been asked whether airplanes would not be endangered by accumulating a load of hoar frost in flying across the Arctic. Fortunately, this risk is less than in winter flying in lower latitudes, because near the pole the water content of the atmosphere is much smaller, owing to the prevailing low temperature.-C. F. Brooks, in "Why the Weather." (Science Service). MID-MONTH WEATHER SUMMARIES FOR RAILROADS To meet the urgent demands of the various railroads and sundry business organizations who must necessarily keep an extensive detailed record of past meteorological conditions in connection with their innumerable enterprises, the Topeka, Kansas, Weather Bureau has been for several years issuing a Mid-monthly Summary of Weather conditions. This has been found to be very advantageous to the Office in cutting down the number of telephone and personal calls for this data. Form 1030-Met'l., the Monthly Weather Summary, is issued as usual, but did not answer the purpose entirely for the business interests because it was received too late for use in settling immediate claims for damages due to the weather elements which might have occurred during the early days of the month.B. R. Laskowski. A NEW LIFE CONTRIBUTING MEMBERSHIP IN THE SOCIETY It is gratifying to be able to present the following evidence of the esteem in which the American Meteorological Society and the Weather Bureau are held by a large public service corporation. This corporation's application for membership was sent in by Mr. Roscoe Nunn, meteorologist in charge of the Weather Bureau station at Baltimore. THE UNITED RAILWAYS AND ELECTRIC COMPANY OF BALTIMORE Dear Mr. Nunn: April 17, 1926. As an expression of our appreciation of the generous co-operation of the U. S. Weather Bureau in our weather observation work, and in order to derive the benefits of an affiliation with the American Meteorological Society, the United Railways and Electric Company of Baltimore desires to become a life member in the grade of Contributing Member of this Association. I am, therefore, enclosing a check for one hundred dollars in payment of the required dues for this membership, at the same time asking if you will be so kind as to sponsor our application. Very truly yours, (Signed) GEORGE F. WEN NAGEL, Asst. Supt. of Power. NOTES FOR CO-OPERATIVE OBSERVERS Although many accounts have been written of the effects produced by lightning, important details are usually omitted, making a scientific analysis of the available information difficult. It is desirable that there be placed on record in an appropriate institution such as the Weather Bureau of the United States Department of Agriculture, any facts relating to lightning stroke. It is necessary in making such observations to note carefully many details that often escape attention. Assuming that the object struck is a tree, a plan of the surroundings showing the location of various other trees and objects, their heights, and the position of fallen pieces of the tree struck, should be made. If possible photographs should be taken from different positions, showing the nature of the damage. All holes, furrows, and other irregularities on adjacent ground should be noted, and their size included. If the tree is splintered, notes should be made of the positions of the most distant splinters, as well as of all the large ones. The nature of the splintering should be noted, as an indication of the path of the lightning. Punctures of the bark should be searched for, even if they are very small. They often show whether the tree was affected by a mechanical force acting from within outward, or the reverse. Their borders may be scorched. The nature and location of all damage to the bark and sapwood should be noted. Nothing should be moved until everything of interest regarding the original effect of the stroke has been recorded. Then, if practical, the tree may be thrown so that the roots may be examined and the nature and extent of injury to them, if any, noted. Exhibits should be collected, carefully labeled, and preserved if it is felt that the information obtained can be made more useful by that means. The Weather Bureau will be glad to make additional suggestions to those who are interested in making accurate records of the effects of lightning strokes. - Clip Sheet, No. 408, U. S. Dept. Agric., April 19, 1926. How to Estimate Cloudiness Some people are interested in clouds for their beauty, their variety, or their effect on the brightness of a day. But the astronomer wants cloudless skies; the meteorologist desires a variety of clouds visible at different levels; the manufacturer needs sunshine to keep his factory lighted and heated free. So the weather observer usually observes cloudiness, mostly in terms of sky cover, sometimes also in terms of density. Without special care it is difficult to gauge tenths of sky cover. The lower half of the sky, particularly, is likely to be underestimated. The sky cover may be approximated by considering the sky divided into an upper half and a lower half by a line at an altitude of 30 degrees above the horizon. The angle of 30 degrees may be found approximately by holding vertically at arm's length a stick half as long as one's arm. If the lower end of the stick is on the horizon, the upper end will be approximately 30 degrees above the horizon. Estimate the number of fifths of the upper half of the sky covered by clouds, whether thin or thick, and the number of fifths of the lower half covered by clouds. The sum of these two numbers is the number of tenths of the sky covered by clouds. Recording sky-cover without cloud density is as unsatisfactory as using a thick blanket for your bed covering regardless of the temperature. Density may be expressed in the following terms or numbers: transparent (0), semi-transparent (1), medium (position but not outline of sun or moon visible) (2), dense (position of sun or moon not visible) (3), very dense (4).-C. F. Brooks, in "Why the Weather." (Science Service). NOTES ON PUBLICATIONS A very valuable summary of the subject of orchard heating as it applies to California conditions has been prepared by the Agricultural Experiment Station of the College of Agriculture, University of California, issued as Bulletin 398, "Orchard Heating in California." It includes the results of a thorough survey of orchard heating practices, costs and results, made in co-operation with Mr. Floyd D. Young, the Weather Bureau's specialist in frost investigations, whose work in the interests of the growers is so widely and favorably known. The Bulletin is distributed free. Reports published in 1925 relative to the abnormally great northward extension of warm water in the region of the Grand Banks found by the Tampa and the Modoc during the ice patrol season of that year, are now supplemented by Bulletin 13 of the United States Coast Guard: "International Ice Observation and Ice Patrol Service in the North Atlantic Ocean, Season of 1925." "The Climate of New York State" is the title of a 38-page Bulletin (No. 444) of the Agricultural Experiment Station of Cornell University, by Mr. R. A. Mordoff. The clearly written text is well supplemented by 39 charts and 4 tables. "Snow Removal in Michigan," (published in the Proceedings of the Eleventh Annual Conference on Highway Engineering, held at the University of Michigan, Ann Arbor) is a 93-page study of the problem by V. R. Burton. The discussion is supplemented by extensive tables, together with some 45 maps and diagrams. Of outstanding climatological interest are perhaps the maps of monthly snowfall-and-wind-direction, diagrams of total annual snowfall from storms of various intensities in upper and lower Michigan, the frequencies of snowfalls of given amounts, and especially a series of charts for many stations showing the relations between snowfall, snow reduction (by natural factors), and air temperature, for the months November to May. John B. Leighly of the Department of Geography of the University of California has prepared the first of a series of "Graphic Studies in Climatology" entitled "Graphic Representation of a Classification of Climates" (Univ. Calif. Publ. In Geog., Vol. 2, No. 3, pp. 55-71, 11 text figures). The study is intended as an aid to the appreciation of Köppen's classification of climates, the latest revised map of which is that contained in his "Klimate der Erde" (1923). There are described and illustrated, "certain simple graphic devices in which the essentials of the Köppen classification are reduced to a few figures based on rectangular co-ordinates," the aim being to "suggest a means for its application to stations and areas through the medium of graphs." BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY Published Monthly by the American Meteorological Society at Worcester, Mass. Address exchanges and all communications other than manuscript intended for the BULLETIN, to "Dr. C. F. Brooks, Secretary, American Meteorological Society, Clark University, Worcester, Mass." Manuscript for the BULLETIN should be sent to "Dr. B. M. Varney, Editor, Bulletin of the American Meteorological Society, Weather Bureau, Washington, D. C." Vol. 7 MAY, 1926 No. 5 SCIENTIFIC PAPERS AT THE WASHINGTON MEETING The papers announced in the BULLETIN for March were, with one exception, presented, and there were three additional papers. Abstracts of these papers, and notes on the discussion that followed each, are given in this and the June issue of the BULLETIN. Under each title is a note relative to publication of the complete paper as far as this can be determined. It is impracticable to follow strictly the order of presentation of the papers at the three sessions, hence the original numbers of the papers as given on page 38 of the March BULLETIN will be retained in this and the June issues. 1. Why the Temperature of the Air Decreases With Increase of Height By W. J. HUMPHREYS The purpose of the paper is to present the essential reasons for the phenomena observed. The need for such presentation is clearly shown by the fact that the "explanations" of the diminishing of air temperature with altitude usually offered are erroneous, due to hasty and inadequate consideration of important details. The correct explanation which. though well known, is certainly not widely known, is here restated in the hope that it may eventually become securely fixed in scientific literature. 1. Between one-fourth and one-third of the solar radiation incident on the outer atmosphere, gets through to, and is absorbed by, the surface of the earth. 2. A roughly equal portion is directly taken up by the air, largely by its water vapor and carbon dioxide, and, when there are no intercepting clouds, generally in increasing amount per unit mass with decrease of height. 3. Earth radiation also is strongly absorbed by water vapor and carbon dioxide, hence, as a rule, decreasingly absorbed per unit mass of air with increase of height. 4. Clearly, then, through absorption of radiation and by conduction |