million dollars a year. Although the causes of forest fires will gradually be reduced by education and law enforcement, there always will be forest fires started by lightning and other causes when conditions in the forest are dangerous. If the dangerous fire conditions, however, can be predicted a few days in advance, the fire protection organization can be prepared to find and suppress fires when they are small and easy to control. . . .

As relative humidity is the most important factor in changing the inflammability of forest materials in summer, the question may be asked: "Why not use relative humidity as an index?" The answer is that relative humidity does not always indicate moisture content consistently, for the reason that changes in moisture content of woody materials lag behind changes in relative humidity of the air. Another disturbing element here is temperature of the air. In nature the three elements-relative humidity, temperature and moisture content of ma

terials are rarely in equilibrium. Moreover, there is an infinite variation in their relations, as a result of not being in equilibrium.

In order to measure the moisture content of duff in place, a recently developed duff hygrometer is being used at the Experiment Station. The instrument consists of a hollow, perforated metal tube containing a strip of rattan which expands and contracts with changes in moisture content and so arranged as to register the changes on a dial attached to one end of the instrument.

Knowledge of the existing moisture content of the fuel, and therefore its existing condition of inflammability, is one of the requirements necessary for making a prediction of inflammable condition in the forest. The other equally important requirement is a thorough weather forecast, in order to know whether the forthcoming weather will bring conditions making for greater or less moisture in the atmosphere and thus greater or less moisture in the fuel. The weather forecast, of course, should be of such a nature as to give this information, whether the changes in the moisture of the atmosphere are to be influenced by rain, temperature, cloudiness or other elements. . . . It is realized that it is exceedingly difficult to make the sort of detailed weather forecasts that are needed. In this connection, Mr. Beals stated in a recent article in the Monthly Weather Review:

“The making of reliable fire weather warnings is even more difficult than the making of frost predictions; and in the latter case it has been proven that the most satisfactory method is to obtain all the information possible regarding the past weather, and then have a man on the ground capable of amplifying a general forecast to meet the conditions over a small area."

This suggests the possibility of having a meteorologist of the Weather Bureau on the ground to work side by side with the men of the Forest Service who are conducting the fundamental fire studies in several localities in the West. So far as the prediction of dangerous fire conditions is concerned, it is believed that this would be one of the most effective ways in which the Weather Bureau could help in the solution of the forest fire problem. (Excerpts.)

MR. BEALS, after asking for remarks, said that he agreed with Dr. Weidman; there must be a man on the ground, to make reports to the

forecaster, and to amplify and adapt the forecasts to the different

areas.

(MR. SHERIER said that he would like to emphasize this; that to meet conditions as they had been outlined by the Forest Service it will be necessary to have a man on the ground, as is now the case in our frost work.

MR. BEALS: The question is an important one, I believe that a committee should be appointed to draft a resolution showing our appreciation of its importance, to be forwarded through the Executive Committee of the Pacific Division, A. A. A. S.; what is your pleasure?

FR. RICARD moved, and it was seconded by MR. SHOW, that such a committee be appointed. The question was put, and the motion carried with no dissenting votes. MR. E. L. WELLS and MR. S. B. SHOW were appointed to the Committee, and were instructed to report before the close of the session.

The CHAIRMAN announuced that owing to the acute fire situation in the State of Washington, MR. GEORGE C. Joy, Chief Fire Warden for Washington State, was unable to be present, and that therefore his paper, "Forest Fire Weather in Western Washington," would have to be withdrawn. He regretted Mr. Joy's absence exceedingly, as a presentation of his views on this subject would have been very enlightening. MR. SHOW was then called on to read a paper by CARLOS G. Bates, Director of the Fremont Experiment Station, Colorado, on

Evaporation as a simple index to weather conditions
By CARLOS G. BATES

The principle upon which the use of evaporimeters has been based, in connection with the study of forest fire weather, is very simple. As, in the continental United States, periods of low barometric pressure are commonly periods of rainfall, so also the intervening periods of higher pressure are usually periods in which drying occurs progressively for several days. A measurement of the rate of evaporation probably expresses, in as simple a term as is possible, the rate at which, and the extent to which moisture accumulated in the forest litter during wet periods, is being or has been dissipated. Every factor which influences the dryness of the forest floor, enters into the evaporation rate as measured instrumentally. Even the time and amount of precipitation can be largely ignored, since so long as the moisture of a rain is retained, its presence will reduce locally the evaporation rate. . .

It appears that the fire hazard is only completely relieved when complete saturation of the atmosphere and of the ground, occurs. While it is doubtless true that the hazard is lessened by any degree of moisture or rainfall, still, owing to the large number of factors entering into the fire situation, vigilance cannot be relaxed unless the relief has been quite complete.

It will, then, be asked, "in what way is the evaporation record superior to the precipitation record?" It is probably superior only in the sense that it leaves little room for judgment as to whether the country has been effectively soaked.

The records of evaporation obtained at six points during the season

of 1923 indicate clearly the character of the variations at any single point and between stations in the same general region. They suggest that the evaporation record comprises a simple means for integrating all of the factors which accompany the periodic changes in barometric pressure, and that this record may have a quantitative value greater than that of any single factor commonly recorded at weather stations-possibly, in relation to fire hazard, greater than any combination of weather elements that might be integrated by computation. It is indicated that evaporation varies so greatly from one point to another nearby point, for any single day, that to be practically useful to a Forest Supervisor the evaporation record must be of a local character. .

MR. BEALS said that this was a very good paper; that evaporation was clearly a better index to fire hazard than was precipitation.

MR. GRANT confirmed this; stating that conditions governing the rate of evaporation are widespread. In Arizona he has six evaporation stations, they all usually vary in rate of evaporation together, showing maxima and minima on the same dates, although there may be differences in actual amount of evaporation, due to local causes.

MR. GRUNSKY stated that there is no method yet devised of absolutely determining the evaporation from a given reservoir or lake surface, and suggested that it would be well for the Society to pass a resolution advocating the adoption of a standard method of measuring evaporation.

MR. LASTRETO suggested that there might be a distinction between evaporation from duff and forest material and that from open bodies of water, which would require different standards of measurement.

MR. BEALS said that the use made of any given data varies as the requirements of the user, but that we should have a standard useful both to engineers and the Forest Service. As to the duff, its humidity varied with the relative humidity of the atmosphere.

RESOLUTIONS

MR. GRUNSKY offered the following resolution:

Resolved that the study of evaporation from open bodies of water should be extended, with particular reference to the standardization of methods of observation, in order that known meteorological conditions may better serve as a basis for predicting evaporation losses from such water bodies.

The adoption of this resolution was moved by FR. RICARD, and seconded by DR. MCEWEN. It was passed with no dissenting votes.

The CHAIRMAN called for reports from the committees which had previously been appointed.

MR. Grant submitted the following resolution from the Committee appointed on the problems of the Lower Colorado River:

Being impressed with the importance of flood control and other problems of the Lower Colorado River and the necessity for an early solution thereof, and realizing that the solution of these problems requires action by the United States because of their interstate and international aspects, be it Resolved by the American Meteorological Society that the attention of the Executive Committee of the Pacific Division of the

American Association for the Advancement of Science be called to the present situation with the suggestion that the Pacific Division place itself on record as favoring early action by the United States to accomplish the permanent solution of these Colorado River problems.

The adoption of this resolution was moved by MR. BLAKE, seconded by MR. ALEXANDER; it was carried unanimously.

MR. WELLS submitted the following resolution from his Committee: Whereas the conservation of the remaining Forest area, and the reforestation of large areas already cut over are largely dependent on the prevention and control of forest fires, and

Whereas in the prevention and control of forest fires a foreknowledge of the weather is most important, and

Whereas the making of weather forecasts for forest areas is difficult, because most of the observation stations are outside these areas, therefore be it

Resolved, that the Congress be asked to appropriate such funds as are needed to provide meteorological stations in the forest areas and to make adequate study of forest weather and to apply the results of this study to forest fire prevention and control.

MR. BEALS inquired whether or not it was proper to petition the Congress.

MR. GRUNSKY said that it was proper, that Congress desired and welcomed such petitions.

Its adoption was moved by MR. WELLS, seconded by MR. BLAKE and MR. GRANT, and it was carried unanimously.

The CHAIRMAN suggested that it would be fitting that the Society offer some token of appreciation to the Pacific Division, A. A. A. S., and to the University of Southern California, for the privileges and conveniences enjoyed during the meeting.

MR. WELLS then moved, seconded by MR. GRANT, that the Secretary be instructed to write a letter to the Pacific Division, American Association for the Advancement of Science, tendering the thanks of the American Meteorological Society for the privilege of meeting with the Pacific Division and of participating in the general meetings; and a letter to the University of southern California, thanking the University on behalf of the Society for the conveniences afforded the meetings. The motion was carried and the Secretary so instructed.

The CHAIRMAN made a last plea to non-members to affiliate with the Society.

MR. GRANT moved a vote of thanks to the members of the Forest Service who had participated in the meeting, which was passed unanimously. MR. GRANT moved a vote of thanks to the Chairman, for his valuable services before and during the meeting. The motion was carried by acclamation, over the protests of the Chairman himself (Mr. Beals). The meeting was then adjourned sine die.

(Signed)

J. CECIL ALTER,
GEORGE W. ALEXANDER,

Acting Secretaries.

"Time and Timekeepers," a large and very thorough book on the subject by Professor Willis I. Milham of Williams College, has just been received from the Macmillan Company for review. Anyone interested in reviewing this book from the meteorologist's standpoint should apply to the Secretary.

The Osservatorio di Montecassino issues bimonthly La Meteorologia Pratica, a review of applied meteorology in its aeronautical, agricultural, engineering, maritime, radiotelegraphic, physiological, etc., phases. Seismology is also included. Any meteorologist who could prepare abstracts of the articles in this journal would be doing a signal service to his fellows who can hardly read even the titles. The Secretary will send the magazine to anyone asking for it.

One Hundred Percent Enthusiasm

During our experience of the last five years in meeting marine observers we have known observers with all degrees of enthusiasm, but it was only today that we found the "Real Scrib."

North River. Captain

Shortly after 2 P. M. our messenger greeted us with: "Mr. Parry, won't you please answer this call? This lady is so excited I can't get the drift of what she wants." Picking up the receiver this is what we heard. "If this is the Weather Bureau, listen hard. This is the SS. Co., Pier is going to take out the -and has just found that he has no Weather Bureau blanks (1201) on board. He is acting like a wild man and wants to get some aboard before sailing at 3 o'clock. Please try to get them here or he may scuttle the ship."

Calling Allan (our messenger) we handed him a pad of 1201's and asked him to get them to Pier if possible before 3 o'clock. He arrived at the elevated station just in time to miss the 9th Avenue train. This cost him 12 minutes' delay and he arrived at the head of the pier just as the gong for clearing was sounded. As he rushed breathless up the pier he was met by a Special Officer who hurriedly asked if he was from the Weather Bureau. Then in a voice that resounded the length and breadth of the Pier he called: "Here he comes."

By this time Allan had become a bit excited himself and increased his speed toward the gangplank, which was replaced for his convenience. He was quickly hustled to the Bridge, delivered his package, and, after receiving the thanks of the Captain he hustled ashore amid the cheers of the passengers and the crowd on the Pier.

The situation was saved and the Weather Bureau assured of two months' observations from the South Atlantic.-Benjamin Parry, Observer, U. S. Weather Bureau, New York, N. Y.

The index for volume 4 of the BULLETIN will be issued with the January BULLETIN, 1924. Additional copies may be had at 10 cents each. Binders for 1923 and for 1924 will also be ready next month, at 15 cents each.