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The measurement of temperature, with some remarks on other physical measurements, and applications to meteorology. E. W. Woolard. Pp. 264


[See May BULLETIN, P. 49. ical treatment of the subject.]

This is a thorough-going historical as well as log

Shading instrument shelters. S. D. Flora. Pp. 271-272, 3 figs.

[Two similar thermometer shelters of the type used by the U. S. Weather Bureau, were placed near each other in a Topeka, Kansas, park, so that one was shaded by a tree and the other was exposed to full sunlight by day and uninterrupted radiation by night. Standard thermometers in each were read daily. In spite of the white paint and the louvred sides which allow the air relatively free circulation, the temperatures inside the shelter in the open went usually a degree or more higher by day and about the same amount lower by night than those inside the shelter in the shade. The extreme differences noted were 7 degrees (F.) each way.]

The standard atmosphere. W. R. Gregg. Pp. 272-273.

[The standard atmosphere pretends to specify normal or standard conditions at various heights. At present there are about as many "standard atmospheres" as there are people who have a need to consider average conditions in the free air. Several are discussed; and the need for a standard based on adequate observations and adopted universally is urged.]

Intervals between beginning of rainfall in west and central France. A. Jagot. Pp. 273-274.

[In half the cases, rainfall begins at Le Mans within 6 hours after the time it began at Brest, or within 3 hours of the time it began at Nantes, the distances being, respectively, 420 and 185 km. The cases are classified according to the position of 'highs' and 'lows,' the most frequent combination for rain being a 'low' over the British Isles and a 'high' over Spain.]

The most intense rainfall on record. B. C. Kadel. Pp. 274–276, 2 figs. [See May BULLETIN, pp. 51-52. Copies of correspondence, a photograph of Porto Bello, Panama, and a retouched photostat of the original record are reproduced.]

Sunshine and cloudiness in the Canal Zone. H. G. Cornthwaite. Pp. 276277, 3 photographs, 1 diagr.


[Panama is in one of the cloudy belts of the earth. But there is, on the average, only one day a month that the sun does not shine, and the longest period without sunshine, for which there is authentic record, was 4 days. Nevertheless, the average daytime cloudiness in the dry season (December to March) is about 50 per cent. and in the rainy season (April to November) about 75 per cent. the dry season the interior and Pacific side have more cloudiness than the Atlantic side, where the wind comes off the sea clear. In the rainy season the nights are cloudy, while in the dry season the daytime, cumulus clouds disappear in the evening.]

Humidity and hot weather. H. G. Cornthwaite. Pp. 277–278.

[Surprising as it may seem, sunstroke and heat exhaustion are rare in Panama. The wet-bulb temperatures range up to 79° F. in July, which is higher even than at some of our hot humid Gulf coast cities. The winds, however, make the weather relatively comfortable. In the dry season, the wet-bulb temperatures are about three degrees lower and the wind movement is greater.] [Six notes on related aspects of physiological meteorology follow this article (pp. 278-280).]

Distribution of average annual and maximum 24-hour and hourly rainfall in Canal Zone. Diagram only. P. 280.

[The Atlantic watershed is markedly wetter than the Pacific, average annual rainfall (162 vs. 68 inches), but the greatest rain in an hour, at Balboa, on the Pacific side, has been nearly 6 inches, as compared with 5 inches on the Atlantic side.]

Agricultural meteorology. J. Warren Smith. Pp. 281-283.

[See June BULLETIN, p. 65. This paper contains a valuable bibliography.] Of the fifteen notes, abstracts and reviews which follow, on pp. 283-288, one on Montana rainfall receives most space.

[On the plains the average rainfall is 13.6 inches, of which 55 per cent. comes in the period from April to July. The variability of rainfall from year to year is considerable, especially at Havre, where there was 26 inches of rainfall in the wettest year, and but 7 in the driest year since 1880. The seasonal and annual rainfalls for each year are shown graphically with columns for each year, the zero of each column being April 1, the beginning of the agricultural year. The rainfall of January to March projects in outline below the zero line; that of April to July in black above, and on top is the rainfall of August-September and October to December shown by distinctive hatching.]


On page 49 of the May issue of the BULLETIN are two abstracts of the papers read at the Washington meeting, one by Mr. E. W. Woolard on "Temperature scales and Thermometer scales," and the other by Professor Marvin, "Shall we adopt a half-degree absolute Centigrade scale instead of the Fahrenheit?"

It may interest some of the members of the Society to know that for a period of 4 years we have been using at Blue Hill a scale devised by the writer, but which entirely unknown to him had been previously suggested. This scale starts from the absolute zero and has a boiling-point of 1366 and a freezing-point of 1000. In March, 1918, I called the attention of the Weather Bureau to the advantages of this scale. It is obvious that the Fahrenheit scale is rapidly becoming obsolete in scientific work and aerographers must choose between Centigrade, the integrated Absolute or some new scale. The Centigrade scale division is too large and furthermore requires in all upper air work the use of minus signs. The integrated Absolute is in use but the scale division is too large. The problem, therefore, is to devise a scale which shall be suitable to physicists and at the same time offer the required detail for meteorological purposes.

In the scale which we have been using there are no minus signs (and incidently the degree symbol may be dropped as suggested by Sir Napier Shaw and reserved for angular measures). There is no confusion in the matter of zero and freezing. The scale divisions are small enough to meet the requirements of aerologists and climatologists. These divisions are approximately one-half of the Fahrenheit and one-third of the Centigrade. In thermodynamics the use of the scale makes for accuracy. Reference to the Blue Hill Observatory reports will show that in a given tabulation there was a saving of 40 per cent. in composition.-Alexander McAdie.

"This scale starts from the absolute zero and has a boiling-point of 1366 and a freezing-point of 1000."

Technically, these specifications are mutually inconsistent and incompatible. If the temperature of melting ice by McAdie's scale is 1000 and of the boiling point is 1366 then 1.00° C. = 3.66. Now, if the scale starts at the absolute zero the temperature of melting ice according to present knowledge must be about 999.55 and not 1000 as stated. Similarly, the boiling-point will fall about 1365.55 and not 1366 as defined. In other words, there are redundancies in the specifications which define the new scale.-C. F. Marvin.

In a later letter, Professor McAdie says that he appreciates Professor Marvin's criticism, and offers further details. He points to the original definition of the

freezing-point on the Kelvin Kilograd scale (cf. Proc. Nat. Acad. of Sciences, Vol. 2, pp. 670–672, Dec., 1916); on which 1000 is the temperature of melting ice at a pressure of a megadyne atmosphere (the normal atmospheric pressure for 106 meters above sea-level). As the melting-point of ice is lowered by increase of pressure and raised by decrease, it follows that 1000 on the Kilograd scale will be about 0.5 of a Kilograd degree higher than o° C. Therefore, if the boiling-point is defined as 100° C. above the freezing-point on the Kilograd scale, it becomes, 1000 + (100)(3.66126) 1366.126, almost exactly 1366. For constructional purposes, then, 1000 and 1366 are usable fiducial points, which will provide a scale close enough to the theoretical Kelvin Kilograd scale for all practical purposes.


"We have been using thermometers thus graduated for nearly five years and find no trouble. Of course, readings may sound a little strange at first, but that is to be expected. The main thing is, we have found it a good thermometer for our purposes. They are made by Green1 and are not expensive. I am having some made here at the Jefferson [Physical Laboratory] with very open scales for special work in connection with water vapor pressure."-Alexander McAdie.

(Note added Aug. 23.)—The trouble is, the author of the new thermometer has violated the fundamental principles which must be observed in defining any thermometric scale. These require that numerical values be designated for the temperatures of two, and only two, known points, which must both be easily reproducible. A desirable thermometer scale is a straight line and it can not necessarily in theory pass through more than two independent points. As Mr. McAdie defines his thermometer, he tries to make a linear scale pass through three points, one of which is both unknown and unproducible. The effort to escape the difficulty by resort to the change of temperature of melting ice by change of pressure is utterly futile and adds confusion to thermometry by proposing a new boiling point which upsets many fundamental thermal relations throughout science.C. F. Marvin.

In taking absolute zero as probably —273.13° C. and from that computing the value of one Kilograd degree to be 1000/273.13, or 3.66126, Professor McAdie left out of consideration the fact that by definition 1000 on the Kilograd scale is about 0.5 of a Kilograd degree above the temperature of melting ice at sealevel pressure. Therefore, the value of each degree according to the present state of our knowledge concerning absolute zero would be (1000 -0.5)/273.13, or 3.6595. The boiling-point of the Kilograd scale, as defined is slightly above 100° C. Thus, 100° C. would correspond to about 1365.5 on the Kilograd scale, just as o° C. would correspond to about 999.5. Without questioning the desirability of small temperature units, is it advisable to have a scale whose freezing- and boiling-points are not the common standard?-Charles F. Brooks.

When it is arbitrarily decided that between any two points in a thermometer scale corresponding to any two temperatures in a temperature scale, there shall be any arbitrary number of degrees, then upon giving one of these temperatures a number, the number of each of all other temperatures becomes fixed. Hence it is redundant to specify three points, and in fact, in the present state of knowledge it cannot be done if one of these three is the absolute zero. The absolute zero is a point in the temperature scale which has never been attained; and its position has not been exactly evaluated by means of the observations at attainable temperatures.

1 Henry J. Green, 1191 Bedford Ave., Brooklyn, N. Y.

The Kilograd scale is, therefore, logically unsound, and cannot be admitted into the system of rational physics. The fact that future corrections to the accepted temperature of the ice-point on the thermodynamic scale will not affect the scale divisions appreciably for meteorological purposes carries no weight whatever as an argument for the adoption of the scale. It would be just as justifiable to define the meter as 1/10,000,000 of the earth's quadrant, and then change all our measures every time a more accurate measurement of the dimensions of the earth was made.

To define the melting-point as 1000 and the boiling-point as 1366 would dispose of the above objection, and also of some of the advantages claimed for the Kilograd scale.-Edgar W. Woolard.


The notion that our winters are now milder than they were in the time of our great-grandfathers is as thoroughly ingrained as the doctrine of infant damnation-and it is quite as persistent. Of all the evidence against the notion none is more conclusive than the history of grape cultivation in Europe. Theophrastus, born 372 B. C., was probably the foremost authority in Greece, in his day, on all matters pertaining to natural history. His writings include a volume on the history of plants and another on the causes of plants. In these he has given an elaborate history of the various species of grapes growing in the Mediterranean basin, and also their distribution. Even twenty-five centuries ago the grape was cultivated in southern Europe to its geographic limits; it is so cultivated to-day, and the essential fact is that its geographic distribution has not materially changed in three thousand years.

The grapes of the Mediterranean basin are semi-hardy. They will survive the winters of California, but not those of New York. They are highly sensitive to conditions of temperature as compared with the cultivated species of the eastern United States. Therefore, one may conclude that no material change in temperature either means or extremes-has occurred since the date of the research made by Theophrastus.

A few years ago a professor in a well-known college expressed a belief that the winter temperature was becoming higher at the rate of about one degree a century. Assuming this to be true, the temperature of the Mediterranean basin in the time of Theophrastus must have been about that of the Arctic coast of Siberia to-day! Quo quid absurdius! Jacques W. Redway.


In discussing the fact that the distribution of date palms in Palestine was the same at the time of Christ as now, Dr. Ellsworth Huntington called attention to the following:1

46 * * * students of glaciation believe that during the last Glacial epoch the mean temperature of the earth as a whole was only 5° or 6° C. colder than at present. If the difference between the climate of to-day and of the time of Christ is a tenth as great as the difference between the climate of to-day and that which prevailed at the culmination of the last Glacial epoch, the change in two thousand years has been of large dimensions. Yet this would require a rise of only half a degree centigrade in the mean temperature of Palestine. Manifestly, so slight a change would scarcely be detectable in the vegetation."

He goes on to point out that there may be considerable variations in rainfall without appreciable changes in mean temperature, and shows that, in respect 1 Solar Hypothesis of climatic changes, Bull. Geol. Soc. America, 1914, Vol. 25, pp. 477-590; this quotation from pp. 537-538.

to rainfall, climate has fluctuated in historic times to a much greater degree than the changes during the last century. Why shouldn't changes be greater in 2000 years than in 100? There is no conclusive evidence, however, pointing to progressive drying up of the earth.

"The changes appear to be pulsatory in nature, but have no definite periodicity. The same phenomena recur in cycles of all magnitudes from the little cycles now in progress to those that have a length of thousands of years. * *

In general the changes vary from region to region in such a way as to suggest that they are due to an alternate poleward and equatorward shifting of the great climatic belts. The matter is more complex than this however, for in the same latitude one side of a continent may differ from the other. So far as can be detected, historic changes of climate do not seem to differ from those of the Glacial period or from the little variations that we see from year to year except in degree."1

Fortunately, glacial eras, as our contemporary, Illustrated World (June, 1920), pp. 619–620; would have us believe, cannot descend upon us "with appalling abruptness from the Arctic across the Northern Hemisphere, sweeping mammoth animals before them," or as "vast mountains of ice, which overwhelmed, in their course, all animal and vegetable life."



The hurricane season is with us again, but unless a tropical cyclone or two appears, the elaborate preparations for the immediate detection of a hurricane and for determining its course will pass unnoticed. On account of the indications which unusual tides and the direction from which swells are coming can give as to the presence and probable movement of a hurricane (see June BULLETIN, PP. 70–71), arrangements have been made for the telegraphic reporting of unusual conditions of the sea at all regular and special Weather Bureau stations on the Atlantic and Gulf coasts south of Cape Henry, Va. Arrangements have been made with scores of American vessel-masters to make and report weather observations by radio twice daily from points south of latitude 40°. The importance of wind movements aloft appears to be great enough to justify considerable attention to them both by careful observations of clouds and by frequent pilot-balloon runs.


It is generally thought that tropical cyclones (hurricanes) move approximately in the direction and with the speed of the air at no great height above the surface. If this be true, it is very desirable to obtain observations of free-air wind conditions on all sides of hurricanes, particularly on the north and west sides. Although working under severe restrictions of funds and personnel, the Weather Bureau is undertaking a campaign of this sort for the hurricane season of 1920, July to November, inclusive. Stations are being equipped and will be operated at San Juan, P. R., and Key West, Fla., in addition to those in the Gulf States at which observations are now being made by the Weather Bureau at Groesbeck, Tex., and Leesburg, Ga.; by the Meteorological Section of the Signal Corps at Ellington Field and Kelly Field, Tex.; and by the Naval Aerological Section at Pensacola, Fla. Moreover, two new stations are being organized by the Navy at Colon and Santo Domingo. These nine stations form a network which, it is believed, will furnish information of great value in the study of these destructive storms and in forecasting their direction and rate of movement. Moreover, the observations will be taken regularly twice each day, irre

1 Solar Hypothesis of climatic changes, Bull. Geol. Soc. America, 1914, Vol. 25, pp. 477-590; this quotation from pp. 537-538.

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