years, and that the individual months exhibit both different periodicities and amplitudes of fluctuation.

By using the statistical method of a moving mean the variations for these months have been compared to each other and to the variations for the same months in two other regions.

By extending the curves one year ahead it is shown that the rainfall for single months can be approximated. By observing the general trend of the curves for the individual months, or groups of months, it seems possible to estimate the most probable dryness or wetness several years ahead. Such extensions and forecasts are not recommended as sufficiently dependable for actual use as yet.

The compilation of records of monthly rainfall by this method may be of value in forestry and other industries.

Dr. Douglass commented on the original work done by Mr. Gisborne in the preparation of his paper, and expressed his interest in the conclusions arrived at.

Dr. F. Napier Denison, Dominion Meteorological Service, Victoria, B. C., then gave a paper, illustrated with lantern slides, on "The Climate of British Columbia."

(Abstract to be published in Mo. Weather Rev.)

In the course of his paper Dr. Denison called attention to the disparity in the results of sunshine records made through the medium of the Campbell-Stokes recorder, as used by the Dominion Meteorological Service, and the electrical recorder, used by the United States Weather Bureau, and in the discussion that followed it developed that the real difference is due to the fact that the Dominion Meteorological Service records "bright sunshine" only, while the Weather Bureau system records sunshine without distinction as to intensity so long as the sun's disc is visible. Mr. Wells thought that meteorological services should pay more attention to the making of observations or measurement of the quality or intensity of sunshine and called attention to the fact that in some localities the human skin seems to become tanned more readily than in others having apparently brighter sunshine.

Dr. Denison stated that he would like to see the recording of sunshine standardized by the various meteorological services, and, if necessary, a correction constant worked out for the two types of sunshine recorders, so that their results might be more nearly comparable.

Owing to the lateness of the hour, the paper by Mr. A. Gael Simpson, U. S. Forest Service, Stabler, Washington, was by common consent postponed to the afternoon session of Friday, June 19.

On motion of Mr. Wells it was voted that the chairman appoint a committee on resolutions, to report at the close of the Friday afternoon session.

Adjournment was then made until 9 A. M., Friday, when a joint session with the Astronomical Society of the Pacific was scheduled.

Joint session with the Astronomical Society of the Pacific, was held in the chapel at Reed College, Portland, Oregon, June 19, 1925, beginning at 9.20 A. Μ.

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Dr. A. E. Douglass presented a paper on "Photographs of Shadow Bands at the Eclipse of January 24, 1925." This was discussed by Dr. Aitken, Dr. Douglass, and Mr. Grunsky.

A paper on "Seasonal Behavior of the Polar Caps of Mars," by E. C. Slipher, was read by Dr. Townley, who followed with some discussion of the paper.

Dr. W. S. Adams presented a paper on "An Attempt to Detect Water Vapor and Oxygen Lines in the Spectrum of Mars with the Registering Micro-photometer."

Dr. W. H. Wright presented a paper on "A Photographic Study of Mars."

Dr. Douglass said that meteorologists should be interested in the atmosphere of Mars; in the fact that it is a comparatively dry planet; that its moisture centers about the polar caps; that it is transferred from season to season from one cap to the other; and that the amount that is precipitated in the migration from one cap to the other is one of the problems of Martian meteorology.

Dr. Robert Trumpler presented a paper on "Observations of Mars." Dr. Douglass gave a brief summary of a paper on "Atmospheric Electricity and Instruments for its Measurement," written by Dr. S. J. Mauchly.

A luncheon of the American Meteorological Society was held in the Japanese Room at Reed Commons, Friday noon, June 19, Edward I.. Wells presiding.

Mr. C. E. Grunsky spoke of his interest in the study of meteorological phenomena and told how valuable he had found weather records in his work as an engineer. He suggested some changes in the method of publishing climatological data, and said the stations should be arranged according to latitude and not alphabetically. He paid a tribute to the excellence of official weather records in Canada and the United States.

Mr. M. B. Summers spoke of the climate of Alaska, calling attention to marked variations to be found, and of the relation of the climate to present and future development.

Mr. E. M. Keyser spoke of the climate of the Canal Zone, and how it had been made healthful.

Dr. F. Napier Denison spoke of the climate of British Columbia.

Dr. A. E. Douglass spoke of the climate of the west coast of South America.

The afternoon session of Friday was called to order at 2.15 o'clock, and was opened with Mr. A. Gael Simson's paper on "Static as an indicator of fire weather."

Mr. Simson credited Dr. J. V. Hofmann with the idea of using static as a means for forecasting relative humidity, the weather element most significant from a fire standpoint. Observations with direction finders at the Wind River Experiment Station and at some U. S. Naval Radio Compass stations made it possible to plot on daily weather maps the approximate positions from which static came.

"Static areas of sufficient intensity to permit bearings were not found to the westward over the Pacific Ocean. Static areas were found to lie between Highs and Lows, centering rather more toward High than the Low. A stationary static center was found to exist throughout all but a few of the winter months in northern Texas and eastern Arizona. Another center apparently exists in Florida and the Gulf of Mexico. This center seems to be entirely separate from the one in northern Texas and is not so sharply defined.

"Bearings on nearby thunderstorms were very difficult to obtain. The static occurs in the form of sharp clicks or crashes and seems to come from all points of the compass. However, reasonably accurate bearings on more distant thunderstorms, say in the Yakima Valley or along the Canadian Border, may be secured.

"Static from nearby thunderstorms produces sharp whipcrack reports in the receivers, but with more distant thunderstorms the sound becomes less sharp and more prolonged until for the remote disturbances the sound becomes a mere grumble or 'grinder'

"While somewhat difficult it is possible to locate local rain areas by means of static. For ordinary showers the static is not so intense as during a thunderstorm, but hail, sleet or rains, when subjected to convective air currents either mechanical or thermal, develop exceptionally strong sustained electrical currents, frequently measuring as high as thirty and forty thousand volts, the voltage being measured on an electrostatic voltmeter in series with the aerial and ground. The actual values were doubtless higher as only glazed porcelain was used in insulating the aerial and considerable leakage must take place at high potentials.

Diurnally, and on the whole, the static intensity curve has much the same as the characteristic diurnal relative humidity curve, that is relatively high during the night and lower during the day. However, it must be borne in mind that a signal of given strength, transmitted on about the same wave as used in these static observations will set up approximately ten times the current on the receiving antenna at 4 o'clock in the morning as it would at 4 o'clock in the afternoon.

"9 A. M. was chosen for the regular morning observation. Static intensity values from observations at 9 A. M. showed that if the static was subnormal the relative humidity for the day would be subnormal, but if the static was above normal, high relative humidity would obtain throughout the day. In other words then, morning static was found to be directly rather than inversely proportional to the day's relative humidity.

"If rains continue over a period of several days the static will gradually fall away to a subnormal value until the rains have almost ceased, when a sharp rise in static will indicate the close of the period and the beginning of drier weather.

"Such is an outline of the present status of the study. The little that has been accomplished so far is purely preliminary to the real study and is by no means to be considered as conclusive."

Dr. Douglass remarked that he is glad to know that some one on the West Coast is making studies of static; that he had some time ago suggested to the Bureau of Standards at Washington the matter of investigating static as affecting radio reception, but that so far as he knew no results of any such research have as yet been published. He and Mr. Norquest, also, stated that they are glad that the pestiferous static of radio reception may after all serve a useful purpose if it is an indicator of relative humidity conditions.

It was with regret that the Society heard from the Chairman that the next paper on the program, "The Semi-daily Weather Chart of the Eastern Pacific Ocean," had not as yet been received from the author, Maj. Edward H. Bowie, U. S. Weather Bureau, San Francisco, California. Major Bowie had been unavoidably detained at San Francisco, Dr. Douglass said, but it had been hoped that his paper could be presented, nevertheless.

Mr. George H. Himes, Curator of the Oregon Historical Society, Portland, Oregon, then gave a paper on "Some Early Weather Records."

Dr. Douglass expressed appreciation of the keeping of long records of this kind and said he wished there were more of them, as they are of great value in studies of climatic cycles.

Symposium on Weather and Forest Fires

Note: It is regretted that limited space prohibits the publication of more than the following barest outline of this symposium. This lack of further presentation cannot, however, detract from the great value of the symposium in bringing together the Canadian and American weather and forest men so concerned with doing everything possible to prevent and control forest fires in the Pacific Northwest. The first symposium on Weather and Forest Fires was published in some detail in this BULLETIN a year ago. Very recently an up-to-date discussion of the subject by E. B. Calvert was published in the Monthly Weather Review, May, 1925. (Cf. brief statement in this Bulletin, June, 1925).

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Mr. Clinton E. Norquest, Meteorologist, U. S. Weather Bureau, Boise, Idaho, opened a symposium on Weather and Forest Fires by the presentation of a paper on the subject "Weather Conditions as related to Fire Control."

The second number of the symposium was by Major C. S. Cowan, Provincial Forest Service, Vancouver, B. C., and was entitled "The Logger's Hazard in its relation to Fire Weather."

Mr. Charles I. Dague, Meteorologist, U. S. Weather Bureau, Portland, Oregon, submitted the next paper, entitled "The Fire Weather Warning Service in Oregon," and this was followed by a similar paper on "The Fire Weather Warning Service in Washington," by Mr. George W. Alexander, Meteorologist, U. S. Weather Bureau, Seattle, Washington.

"Primary Factors Governing the Action of Forest Fires," was next presented by Mr. W. B. Osborne, Jr., United States Forest Service, Portland, Oregon.

Discussion of this paper was participated in by Messrs. Gisborne, Cowan, Wells, Joy, and others. Major Cowan took issue with Mr. Osborne, who had stated that a moderate wind attending a fire at the base of a hill constitutes as great a hazard as a fire on level ground with a brisk wind. He said that in the Canadian provinces the worst fires to spread are those that occur on level ground.

Mr. George C. Joy, State Supervisor of Forests, Olympia, Washington, stated in discussing Mr. Osborne's paper that two elements are necessary to produce a crown fire or conflagration in the forest, viz., the starting of a fire, from whatever cause, in just the right location, and meteorological conditions favorable to its propagation.

Mr. Joy then presented the last paper of the symposium, on the subject, "Applied Meteorology in Forest Fire Control and the Abatement of the Smoke Nuisance."

This was followed by an informal address by Dr. F. Napier Denison, Dominion Meteorological Service, Victoria, B. C., on the fire weather service in British Columbia. He stated that the radiographic reports received by his office from ships at sea are of great value in interpreting the movements of high and low pressure areas in connection with their relation to fire weather. Thrice-daily observations of humidity are made at ten places within the Province of British Columbia, and are telegraphed at 5 P. M. to the central station at Victoria for use in framing the fire weather forecasts, which so far this season have had a gratifying degree of accuracy of verification, he said.

Mr. W. D. Humiston, Potlatch, Idaho, discussed the need of fire weather forecasts in northern Idaho, and Mr. Gisborne told of the method of obtaining the forecasts for use at the Priest Rapids Forest Experiment Station, and of the gratifying accuracy that characterized the forecasts last year. Mr. Keyser stated that the State forecasts for Idaho could be repeated by the Spokane Weather Bureau office to the interests represented by Mr. Humiston.

Next followed an informal discussion of the distribution of fire weather forecasts by radio, as a result of which the Chairman appointed a committee consisting of Messrs. Norquest, Alexander, Dague and Cowan, to co-ordinate the radio distribution of weather information in the Pacific Northwest and British Columbia.

The Chairman then called for the presentation of any new business, upon which Mr. Summers offered the following resolution, which was unanimously adopted:

WHEREAS, there has recently been removed from our midst by death, Mr. George N. Salisbury, after a period of 42 years of continuous service in the Weather Bureau; and

WHEREAS, by his ability and untiring application to duty, Mr. Salisbury contributed much to the advancement of meteorology, especially during the 29 years of his supervision of the Seattle Weather Bureau office and the Washington Climatological Service; be it therefore

RESOLVED, by the American Meteorological Society, in session at Reed College, Portland, Oregon, that in his passing the meteorological profession has suffered a distinct loss and the public an able and faithful servant; that this resolution be spread upon the minutes of the Society, and that a copy be sent to his widow and family.