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that indoor humidity cannot be kept at 70 per cent. in this climate. Mr. Miller
thought that the work of Zunss, and of the N. Y. Ventilating Commission and
Yandell Henderson's experiments with aviators, may provide information of
value in a study of the dependence of diseases on the weather. Dr. Edson re-
marked that Zunss dealt largely with the effects of changes of altitude on people
who move.
He said, we just keep on quoting others: we need to learn more for

Comment by the author-In the discussion the point is overlooked that the paper covers mass data of thousands of cases and, with the exception of influenza and lobar pneumonia, the same territory and method of compilation. The elements of crowding, school contacts, laxness of physicians in rendering reports promptly, and the like, which are so confusing in the study of epidemics, to say nothing of the fact that epidemics spread like a forest fire and the weather at the focus or start, is the factor of importance, these while doubtless having an effect on the beginning, closing, and amplitude of the mass curve, leave outstanding in the mass data important differences in the disease curves and it is these differences and their relationships to the average weather for the same time and terrain that the author has emphasized. Crowding is a favorite explanation of epidemics, but does it explain? School contacts is another favorite, but the modern opinion is that children are better off in school during an epidemic than out of school. John R. Weeks, Binghamton, New York, March 5th, 1921.

In reply to Mr. Miller's remark that indoor humidity cannot be kept at 70 per cent. in this climate, Mr. Weeks states that it can be done if the rooms are not overheated. [For example, at 60° F. the dewpoint would be 50° if the relative humidity were 70 per cent., whereas at 70° the dewpoint would be 60° for the same relative humidity. The walls of the room would get wet with condensed moisture if their temperature fell below the dewpoint.] Mr. Weeks cites the following excerpts from an article, "How I run my school," by W. E. Watt, in The Ladies' Home Journal for Sept. 1; 1910, p. 20:

"In my school [Graham School, Chicago] I have had holes drilled into the warm-air chambers, and inserted three-quarter-inch pipes with steam cocks, through which live steam right from the boiler is delivered where it will do the work of humidifying the air before it reaches the school rooms. This enables us to turn off the heat to a great extent. Air that is naturally humidified does not need to be hot for comfort. Sixty degrees is warm enough if you have enough humidity in the air, and I fix our thermostats at that figure..


"Now what is the result of my pupils' studying in this right atmosphere. Their skins are not parched; their eyes, ears and other sense organs are not dried out; their breathing apparatuses are not filled with disease; and their bodies are not weakened so that the least effort wearies them. They are free from those habitual headaches which they formerly suffered daily. They are able to think. They have a natural desire for knowledge. They can remember what they have read. They are enabled to think naturally. Now that is not theory-I am writing from what I have actually tried...

"And for the information of engineers and Boards of Education I may say incidentally that we burn from eighteen to twenty per cent. less coal than other schools of the same architectural pattern!"

Coöperation between meteorologist and physician. Carrol E. Edson.

[The following gaps in medical knowledge touch closely upon the work of the meteorologist:


(1) Is basic metabolism different in people living at high altitudes from that of people living at low altitudes? A study of this might be called "Climatic physiology."

(2) What is the effect of sudden changes-changes of altitude, temperature, moisture, wind, etc.? Experimental solution of this question is possible. This is "Physiologic meteorology."

(3) Lastly, there is the study of the adaptability of the diseased mechanism to meet sudden changes: "Medical climatology."

Among the advantages of a change of climate for a sick person, is to be mentioned the change of physician.

The meteorologist can assist the physician by putting his weather statistics together in special ways. For example, the day should be separated from the night data, and there should be indications of the frequency, degree and duration of departures from the average. Here is an opportunity for a joint committee of the American Meteorological Society and the American Climatological and Clinical Association to determine the right form of tabulation of data.]

When asked to give some of his ideas in more detail he invited the inquirer and others who might be interested to come to Lenox, Massachusetts, on June 10, 1921, to hear his presidential address before the American Climatological and Clinical Association.

Standard methods in meteorological measurements of heat and light. Eric R. Miller.

[New apparatus of Dorno for measurements of sun and sky radiation, and sky polarization. Proposals of Dorno for international coöperation in making comparable observations.]

Prof. Marvin remarked that a new type of recorder was being developed by Prof. H. H. Kimball. J. Patterson said that the use of potassium cells introduced difficulties because of the accumulation of charge, and that different types of cells give results that are not comparable. Mr. Miller said that Dorno's cells appear to remain constant for a year.

(To be continued.)

Issued Jan. 4, 1921

(Concluded from Jan. No.)

*The relation of prolonged tropical droughts to sunspots. W. H. Pickering. (Pp. 589-592, fig.)

[A study of the collected rainfall data covering the last 50 years in the island of Jamaica has shown that there have been 12 droughts, 9 of which have followed closely after a sun-spot maximum or minimum. It appears that droughts occurring after the maxima show a greater deficiency of rainfall, and last longer, than those occurring after the minima. On the basis of sun-spot data a drought, predicted in March, 1919, to begin during 1919 or 1920, actually began in June, 1919, and was continuing at the time of writing the paper. It is suggested that the cause of the variations of rainfall may lie in the effect of changes in ocean temperatures on condensation and evaporation in the Tropics, and the increased solar magnetic activity after sun-spot maxima, although the reason for such a relation is not apparent.-C. L. M.]

*An approximate seven-year period in terrestrial weather, with solar correlation. H. W. Clough. (Pp. 593-596, fig.)

[Investigators of the correlation between terrestrial weather and solar activity have generally agreed that high temperature is associated with a minimum of sun-spots in the 11-year cycle, and vice versa. This relation is most clearly de


fined in the Tropics, but with increase of latitude the amplitude decreases, and there is a tendency to the formation of a secondary crest, which approaches in amplitude that of the primary crest.

A seven- or eight-year cycle has been independently noted by many investigators in the variations of temperature, pressure, and precipitation.

The writer presents data and curves for the United States showing the persistence of a cycle in temperature averaging 7 years from 1790 to 1919. The length of this period varies systematically and periodically over an extreme range of 4 or 5 years in a cycle of about 35 years. These variations synchronize closely with similar variations in the length of the 11-year sun-spot period.

The combination of the 7-year and the 11-year periods results in the subordinate crests found in the curve of the 11-year variation in temperature, and probably accounts for the period averaging 21 or 22 years noted by many investigators. Author's synopsis.]

A mechanism of climatic cycles. (Review reprinted.) (Pp. 596-597.)

Effects of heavy rainfall on Panama Canal slides. H. G. Cornthwaite. (P. 597.)

[It was generally believed by engineers, as well as by the public, that these slides would be most active and troublesome during the season of heavy rainfall. As a matter of fact, the opposite proved to be the case. Practically all of the extensive deep-seated troublesome slides displayed greater activity in the dry season than during the rainy season. The explanation offered by geologists was that the cohesiveness of the material in the canal banks is greatest when the material is saturated by the heavy rains, enabling it to stand up better than it does during the dry season, when it dries out, tending to lose its cohesiveness and crumble under the weight superimposed upon it.-Author's statement.]

The section of the Review on "Notes, abstracts and reviews (pp. 598-601), contains the following: New marine observatory in Japan, Method of preparation of marine meteorological forms, Wandering storms, Progress of meteorology, Annual report of the British Meteorological Committee, Annual report of the Chief of the Weather Bureau, 1919-1920, Composition of the atmosphere, The light from the sky, On the diurnal variation of temperature in the Antarctic, Smoke-travel from great forest fires in Russia, Meteorological Service in Palestine, Obituary of Alexander G. Supan, Obituary of Dr. Max Margules [died of starvation in Austria].

The rest of the Review, pp. 601-625, 15 charts, contains the usual monthly bibliography, summary of solar and sky radiation measurements during October, 1920, solar constant measurements at Calama, Chile, the weather of the month, and seismological reports.

(Issued February 3, 1921.)

The November issue of the Review contains 10 contributions, mostly short ones, and 19 notes, abstracts and reviews. The contributions are noted below: *Flying weather in the southern Plains States. J. A. Reihle. (pp. 627-632). 5 figs.

[This paper is a study of wind and weather as they affect the business of flying. Tables of average free-air winds have been computed for the first two years of pilot balloon observations at Broken Arrow and Fort Sill, Okla., and for one year at Fort Omaha, Nebr. The annual means are based on 1,237 observations at Broken Arrow, 1,098 at Fort Sill, and 567 at Fort Omaha. By applying to the mean velocities the mean gradients from each level to the next higher level from the surface up, discontinuities due to fewer observations at

higher altitudes have been to a large extent eliminated. Average directions were computed separately by trigonometry.

Because balloon ascents are made at times when the wind is too light for kite flights, a comparison of mean velocities obtained by kites and balloons shows a slightly smaller mean velocity in summer by balloons. Another fact brought out is that the direction at high altitudes at both Oklahoma stations has a stronger northerly component in summer than in any other season.

The general eastward drift of the air at high altitudes is conspicuous at all stations; marked differences, however, occur from time to time under similar surface pressure distribution, and these differences are largely the result of abnormal surface temperatures.

Velocities in the free air are somewhat smaller over Oklahoma than at stations farther north and this fact, together with the comparatively mild winters, is favorable for the growth of aviation in this region. Transcontinental flying, too, can be continued throughout the year at this latitude while a considerably more northerly route would often be closed by inclement weather.

Low clouds and rain constitute the most frequent unfavorable condition for flying; fog is serious, but too infrequent to be of importance; while high winds are of intermediate importance.-Author's synopsis.]

Surface winds and lower clouds. F. E. Hartwell. (pp. 632–633.)

[An examination of the year's record of pilot balloon flights at the Burlington station of the Weather Bureau from November 1919 to November 1920, covering 186 determinations of the direction of lower clouds, 546 determinations of direction of wind at 500 meters, and 495 at 1000 meters above the earth's surface, shows percentages of 15, 20 and 14, respectively, coinciding with the surface direction, using the sixteen-points scale. These determinations are reduced to the eight-points scale employed in ordinary surface meteorological work, and show that an error of more than six out of ten, varying from 45° to 135° would result in assuming the direction of lower clouds to be the same as that of the surface wind.-Author's synopsis.]

The highest aerial sounding. W. R. Greeg. (p. 633.)

[Doubt is thrown on so-called world records. ]

(With dis

Local peculiarities of wind velocity and movement: Atlantic seaboard, Eastport, Me. to Jacksonville, Fla. S. L. Trotter. (pp. 634-637), fig. cussion by A. J. Henry.)

[In general, the wind velocity at Weather Bureau stations along the Atlantic coast is greatest on the major projections of the coast and least in the indentations. There are marked local peculiarities, however, which are not explicable wholly by the immediate surroundings of the anemometer. High average wind movements are characteristic of those stations with appreciable water surfaces to the northwest, whence come strong winds most frequently.-C. F. B.]

The accuracy of wind observations in large cities. G. Hellmann. Abstract. [The necessity of observing the direction of the wind from wind vanes has led to the placing of vanes on buildings in cities which are but poorly exposed to the wind, and, being influenced by eddies and deflected currents from adjacent buildings, they not only fail to agree in results with those exposed in openly, but also disagree with other poorly exposed vanes.-C. L. M.]

Ground temperatures compared with air temperatures in a shelter. George Reeder. (pp. 637-639.) Fig.

[A series of observations was made at the United States Weather Bureau station, Univeristy of Missouri, Columbia, during the months of September and October, 1907, to determine how much exposed thermometers on the ground differed from sheltered thermometers 11 feet from the ground. To test the problem further, three beds were made, one of bare soil, one of blue-grass sod, and one of sand. Observations made during the passage of cumulus clouds and upon the effect of a shade area 20 feet distant showed that all the instruments responded to cloud shadows, but that only ground thermometers showed the effect of the building shadow. The latter shadow caused a perceptible


movement of air toward the sunlit area. This paper serves to present the collected data from these observations.-Author's synopsis.]

The cooling of the soil at night, with special reference to late spring frosts. T. B. Franklin. (pp. 639-640.) Abstract.

[The author presents a formula for forecasting the minimum surface-soil temperature and compares this minimum with the air temperature immediately above.]

Effect of soil on frost damage. (p. 640.)

[In a letter to Science (Mar. 28, 1919, pp. 310-311), Mr. T. G. Dabney describes the effect of the onslaught of a killing frost upon vegetation growing upon soils of different character. It was observed that cotton growing in the river silt near the old river bank of the Mississippi was not damaged, but that that growing back from the river bank in the heavy clay, known locally as "buckshot," was completely killed. The explanation offered was that the radiation from the silty soil during the cold night was sufficient to protect the plants, while the clay did not possess this property. The cold night was not preceded by other cold ones but came suddenly when the soil was warm. The country in the vicinity was very level.-C. L. M.]

Predicting minimum temperatures from the previous afternoon wet-bulb temperature. J. Warren Smith. (p. 640.)

[A brief discussion of Anders Ångström's "Studies of the Frost Problem, I."] The influence of cold in stimulating the growth of plants. F. V. Coville. Abstract (pp. 643-644).

[It is the general belief that dormancy in winter of our native trees and shrubs is brought about by cold weather, and that warm weather is of itself sufficient to start new growth in spring. Mr. Coville shows that both of these ideas are erroneous. Experiments indicate that chilling is necessary before the dormant period can end, and the author believes that the cell walls are weakened by cold, thus permitting the starch to be turned to sugar by the enzym, which "leaks" through.]

(To be continued.)


The fifth meeting of the American Meteorological Society will be held at the Central Office of the U. S. Weather Bureau, Washington, D. C., on Monday, April 18, 1921. The sessions are to begin at 2:00 and 8:10 P.M. The 18th was chosen in order to bring the meeting into accord with the program of the American section of the International Geophysical Union which will meet in Washington, April 18-20. On Tuesday morning, the 19th, there will be a joint meeting of the sections on Terrestrial Magnetism and Atmospheric Electricity and on Meteorology. Titles and abstracts of papers to be presented at this meeting should be in the hands of the Secretary by April 3rd.

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