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during February. This is an increase of 24 per cent over the record of January and 86 per cent more than February last year. About two-fifths of this number were inspections of fruits. Requests declined for lack of time were 147.-Weather Crops, and Markets, March 18, 1922, p. 227.

Shipping Snow Unintentionally

A flat car loaded with lumber in the Pacific Northwest showed a heavy diminution in weight on arrival at destination in a drier climate. The consignee and the transportation agents made an examination of the daily records of temperature, rain and snow at the places of origin and destination, and at all intermediate points, at the time the car of lumber was located at or passing through these places. The natural drying of the lumber by being moved from a moist to an arid climate would account for some loss in weight, a fair estimate of which could be made from the temperature and humidity records; also the occurrence of rain on the lumber would tend to offset the drying, if not actually increase the weight temporarily. But the most important factor discovered in the weather records was a fall of 8 inches of snow at the place the car was loaded, between the time of loading and starting on its journey. The weight of 8 inches of snow was rather easily computed, having at hand also the melted equivalent of precipitation, as shown by the local weather record.—Climatological Data, Utah Sec., Jan., 1921, p. 1.

Effect of Velocity and Humidity of Air on Heat Transmission Through Building Materials

J. A. Moyer, J. P. Calderwood, and M. P. Helman. (Ann. Rpt. Penn. State Col. 1915, pp. 55-62, pls. 6.)

Experiments on heat transmission through glass, common red brick, and diatomite insulating brick are reported.

"These data show that the transmission through glass and red brick are increased very materially with increase in humidity. Thus for glass the unit transmission was increased 0.25 B. t. u. by increasing the humidity from 74 to 84 per cent, which is equivalent to a change of 24 per cent in transmission for a variation of 10 per cent in relative humidity. For red brick the unit transmission was increased 0.102 B. t. u. by increasing the relative humidity from 80 to 90 per cent, which is equivalent to a change of 15 per cent for a variation of 10 per cent in relative humidity." -Experiment Station Record, 38, Jan., 1918.

The Absorption of Moisture From the Atmosphere by Wools A. M. Wright (Jour. Soc. Chem. Indus., 28, 1909, No. 19, pp. 1020-1022.) The purpose of this investigation was to determine under what conditions wool absorbs moisture from the atmosphere, and what constituents cause it to absorb relatively large amounts.

The results are summarized as follows: "The relative humidity of the atmosphere (influences the absorption of moisture), more moisture being absorbed during a period of high relative humidity than when the humidity is low. Pure wool fiber, of which greasy wool contains from 50 to 70 per cent and slipe wool about 75 per cent, can absorb from 18 to 20 per cent of its weight of moisture from the atmosphere, but this amount is not sufficient to account for all the moisture absorbed by the dry normal wool fiber. Natural wool fat, present in greasy wool to the extent of nearly 17 per cent and in slipe wool to 61⁄2 per cent, is capable of absorbing about 17 per cent of its weight of atmospheric moisture. Suint, or wool perspiration present in greasy wools to the extent of nearly 13 per cent, and in slipe wools to about 2 per cent, is very hygroscopic, and can absorb from 60 to 67

per cent of its weight of moisture when exposed to the atmosphere. Fatty matter other than natural wool fat, present in slipe wools to the amount of from 2 to 6 times that found in greasy wools, and picked up by the wool from the greasy underside of the skins during the washing process, has a retarding effect on the amount of moisture absorbed.-Experiment Station Record, 22, March, 1910.

AGRICULTURAL METEOROLOGY.

Tree-Top Fruit Damage by Frost.

From time to time our attention is called to frost damage of fruit in the tops of trees while that in under portions escapes damage. Sometimes the reason for this localization is quite apparent, as in the case of the freeze of Dec. 9, 1919, in the Roswell, N. Mex., fruit district, when the movement of a sheet of colder air affetced the tree-tops but not their lower portions.1 On other occasions, local cooling seems to be largely responsible.

Mr. Joseph L. Cline, Meteorologist, in charge of the Weather Bureau station at Dallas, Tex., has reported the occurrence of a tree-top freeze which occurred in a hillside orchard south of Dallas on April 5, 1920. His statement is as follows:

About midway on the south side of a long sloping hill, Oak Cliff, small peaches were killed at the top of trees while a light crop still remains on the middle and lower branches. Grapevines at the same place, 4 to 5 feet above the ground, were at the time of the frost loaded with small grapes. The top leaves and some bunches of grapes, where the vines extended along a fence between the fruit trees and exposed upward, were killed; otherwise the vines and grapes were not damaged. The fruit trees and grape vines had put on leaves, and the foliage apparently protected some peaches and grapes from being killed.

The frost and freezing temperature did not do any damage to garden truck on the same hillside in a garden adjacent to, and south of the fruit trees. Young beans and potatoes in the garden at a lower elevation than the fruit trees did not show any sign of damage.

As local topographic features do not present such an opportunity for top freezing by transported air as at Roswell, and in absence of a definite knowledge of what the actual conditions were, the following explanatory suggestions are offered by Dr. W. J. Humphreys:

1. The actual wind may have been sufficient to prevent inversion, and hence to keep the air at the top of the trees slightly colder than that about the lower branches.

2. In addition to this, and probably much more important, the top portions of the trees lost heat by radiation faster than did the sheltered lower branches, and hence became colder. The contrast should have been more marked on this south slope than would have been the case in a northward-facing orchard, for the southward sloping ground must have been warmed considerably by the sunlight on the preceding day.

3. Finally, the upper portions were more exposed than the under, to the early morning sunshine, an important factor in the killing of frozen fruit.

That the level of maximum cooling in an area of low trees in leaf is about the tree-tops is occasionally to be seen in the formation of a thin radiation fog resting on or enclosing the tree-tops in a wooded depression while the air below is clear.-C. F. B.

Monthly Weather Review, Jan., 1920, vol. 48, pp. 24-25.

Old Farming Theories Upset.

Many of the old theories and actual practices in other sections are absolutely worthless in the "desert farming" areas of Washington, according to M. A. McCall and Henry F. Holtz in a recent Experiment Station bulletin. Even fall plowing, the best in "old Iowa," does not equal early spring plowing, nor does the much-talked of "dust blanket" of the Middle West find a place in this dry land agriculture. The problems are getting moisture and holding it; and under the climatic conditions in this section, the loose soil mulch which is desirable for holding moisture, is a poorer "sponge" than a comparatively firm soil.

The "dry belt" of the Pacific Northwest has been a stumbling block for many prospective farmers, so that those who are successful must produce their crops at a minimum cost. Usually the best results are secured with the least cultivation, so that the average hired man's method of plowing, that is as shallow as the plow will stay in the ground, is the popular and productive method for this type of agriculture because the most moisture is lost from a deep layer of loose soil. Experiments have proven the farm practice of disking instead of plowing to give as good yields in some sections.

Successful farming in such a climate requires a knowledge of local conditions and the proper application of economy and "dry farming" principles.-Science Service.

Rust Spores Sail 10,000 Feet in Air.

This past spring and summer the scientists exposed slides smeared with vaseline from airplanes at various heights at widely different points, and they found that in the upper regions of the atmosphere, even higher than 10,000 feet, pollen grains and spores were abundant.-Science Service.

Advantages of a Dry Climate.

Several cars of stone fruit shipped from Utah in 1919 were found to be spoiled on reaching destination, due, the transportation agents claimed, to Brown Rot, which was found on the spoiled fruit. There was a shortage of cars that season and the fruit was slow in moving after it was delivered to the railroad company, according to the statement of the Utah shippers. The fruitmen further averred that plant pathologists had at various times sought for this disease in Utah but had not found it because of the dry climate. The daily temperature and precipitation records for all the cooperative weather stations in the county where the fruit originated, showing that the 1919 summer was one of the warmest and driest of record in tuat locality, were furnished to the contestants as an aid in deciding whether the Brown Rot spores found in the fruit actually originated in Utah, or were lodged in the empty cars as a result of a previous use.— Climat'l Data, Utah Sec., Aug., 1921, p. 1.

Climate Affects Alfalfa Seed Sale.

The Utah Farm Bureau in offering the Utah alfalfa seed crop for sale through eastern state farm bureaus, was informed by the Michigan State Farm Bureau, of Lansing, that "Utah seed, originating as it does mostly from more southerly climates, and not having the severe winters that we have, in its present habitat, has not proven hardy enough for our conditions." In reply comparative weather data were furnished for Deseret, Emery and Fort Duchesne, Utah, as representing the districts from whic seed was being offered. These data were compared directly with sin values for Lansing, covering the average monthly, mean maximum, mean minimum, monthly extreme highest and lowest temperatures, and the

average dates of latest killing frost in spring and the earliest in autumn, which show that the Utah seed is acclimated to somewhat more severe temperatures than those prevailing at Lansing, the Utah temperatures being higher in summer and lower in winter, with greater daily ranges, and a shorter summer season between frosts.-Climat'l Data, Utah Sec., Nov., 1920, p. 1.

Travels of Orchard Heaters

Mr. A. M. Hamrick, in a recent issue of the Monthly Weather Review, discussed the decline of orchard heating in the Grand valley of Colorado during the past six or eight years. His remarks were of particular interest in view of the fact that there was a contemporaneous renaissance of orchard heating in the Pecos valley of New Mexico.

The character of the springs, as regards killing freezes, I think furnishes the explanation in each case. These two valleys are on opposite sides the Rocky mountains, and a disastrous spring in one is more than likely to be a favorable season in the other. The Grand valley has been fortunate in the matter of spring freezes for a number of years, while six of the past seven springs have been disastrous to unprotected orchards in the Pecos valley.

The average orchardist seemingly is as irrational as a child, and forgets a lesson almost as quickly; this statement, I believe, will be endorsed by all meteorologists who are as close to their clientele as I am. If he "gets by" for a few springs in succession, he will conclude that orchard heating is not profitable.

Several carloads of orchard heaters were shipped from the Grand valley to the Pecos valley early this year. Now let the springs of the next few years be disastrous to the Grand valley orchards, with favorable springs in the Pecos valley, and it is probable that there will be a reflow of heaters from the Pecos back to the Grand. In fact, it is not impossible that some Grand valley orchardists may at some time in the future buy back some of the heaters he sold this year.-Cleve Hallenbeck.

On Dec. 29, 1921, at Toronto, the Botanical Society of America and the Ecological Society of America, held a symposium on "Frost Resistance, Hardiness and Winter Killing of Plants:"

1. Geographical distribution of low temperature conditions. Forest Shreve, Tucson, Arizona.

2. Observations on hardiness in Canada. W. T. Macoun, Ottawa, Can. 3. Relation of water retaining capacity to hardiness. J. T. Rosa, Jr., Columbia, Mo.

4. Effect of low temperature storage and freezing on fruits and vege tables. L. E. Hawkins, Washington, D. C.

5. A colloidal chemical basis for resistance to low temperatures. R. Newton, St. Paul, Minn.

6. Physical and chemical studies of fruits in storage. J. R. Magness, Canton, Penn.

7. Hardiness from the horticultural point of view. M. J. Dorsey, Morgantown, W. Va.

Prizes for essays on meteorological and phenological observations during the preceding year are offered annually to girls and boys under 18,

either resident, or attending school in the parish of Enfield, Middlesex, England.

PAPERS PRESENTED AT THE TORONTO MEETING
(Continued from March BULLETIN, p. 40.)

Military Meteorology. William Gardner Reed (formerly Major, U. S.
Signal Corps).

Military meteorology began with the Great War of 1914-18. The problem is in part that of pure meteorology, and in part that of military tactics. An expeditionary force on foreign soil presents the best example of the problems, and the conditions under which such a force operates set limits to the methods employed.

Military meteorology falls into three groups: statistical meteorological information, current meteorological information, and forecasts. Statistical information includes that required in connection with more or less permanent military installations with the distribution of material and personnel through the area of operations, and is of particular importance in determining the locations of airdromes, especially with reference to wind conditions and fogs.

Current information is necessary mainly for aircraft, artillery, and sound ranging units. An important phase is that of furnishing "ballistic winds" for use of the artillery. The equipment of military meteorological stations is similar to that of the ordinary meteorological station, including equipment for pilot balloon observation. Single theodolite observations are preferable to those with two theodolites because of front line conditions.

Military forecasting is not unlike civilian forecasting except that it must be adapted to problems of operations officers, and in some cases the meteorological officer must forecast for regions with which he is not familiar.-W. G. R.

Discussion. W. J. Humphreys mentioned that J. Rouch had written a book on military meteorology. R. DeC. Word emphasized the military importance of statistical meteorology. If armies had had proper meteorological information in advance they would have got along much better. They would not have been surprised by fog in Flanders, nor would they have failed to be supplied with water at Gallipoli.

Later, Major W. R. Blair sent the Secretary a copy of Information Bulletin, No. 12, Feb. 1, 1922, U. S. War Dept., Off. Chief Signal Officer, from which the following excerpt is taken:

MILITARY OPERATIONS AND WEATHER

It is surprising, to one who reads of military operations, the number of times he finds weather referred to as an important factor in the outcome of these operations. That weather is always a factor that must be given consideration in planning any military activity is generally admitted, but it is doubtful if the importance of this factor is fully understood by the average officer. In "The Outline of History," H. G. Wells says, in describing the war between the Greeks and the Persians, which occurred 480 B. C.

"The Hellenic fleet retreated before the advance of the Persian shipping, which suffered seriously from its comparative ignorance of the intricate coasts and the tricks of the local weather. . . . The Persian fleet, coasting from headland to headland, accompanied this vast multitude during its march southwards; but a violent storm did the fleet great damage and 400 ships were lost, including much corn transport."

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