The system in use here is not without a rival. Some weeks ago, it was announced that regular radio broadcasting of a weather map from Munich, Bavaria, had already been begun. The European plan embodies an ingenious application of electricity directly to a sensitized paper for reproducing the map. The scheme is in essence this: An original map is drawn in non-conducting ink on a conducting sheet of metal, which is then mounted on the revolving cylinder, as in the Jenkins system. Upon this sheet rests a very fine sylus which as each non-conducting ink line passes under it, opens a circuit that attends to the sending of the radio impulses. On the receiving cylinder is a sheet of paper sensitized to the action of electric currents in such a manner that each dot or dash registered upon it by a stylus is faithfully reproduced when the paper is "developed" by some suitable process. It appears thus that the "photographic" stage (there is of course no real photography about it) comes at the end of the whole train of mapmaking operations—at each receiving station, in other words. What the advantage or disadvantage is, in point of total time consumed in disseminating the map, we do not know as yet. The time used in the actual transmission is reported as being only about five minutes.-B. M. V. THE WHITE MAN AND THE TROPICS Dr. E. S. Sundstroem of the University of California Medical School is the author of a 216 page report entitled "Contributions to Tropical Physiology, with special reference to the adaptation of the white man to the climate of North Queensland" (Univ. Calif. Publ. in Physiology, vol. 6, pp. 1-216). Dr. Sundstroem was resident in 1920-1922 at the Australian Institute of Tropical Medicine at Townsville, Queensland, where he carried out intensive studies, upon himself and others, of a wide range of physiological phenomena. One chapter of the report deals with "Measurements of Cooling Power," and it is mainly from this chapter, and from the Introduction and the Postscript and Resumé that the excerpts below are taken. It is hoped, by making these excerpts rather extensive, accurately to set forth the author's point of view upon the few matters with which it is possible to deal in this note. Dr. Sundstroem points out at once that he “harbors no illusions regarding the finality of his conclusions, especially in those parts of the work which, he believes, have for the first time become subjects of systematic experimental inquiry." He holds, nevertheless, that his data, collected with all possible care, indicate that the climatic factor per se and apart from the factor of tropical disease, must be reckoned with. The writer disagrees in this respect with opinions held in some quarters that the hot climate itself is a negligible factor and that diseases of exogenous origin or faulty diet are the only obstacles to tropical settlement by the white man. On the other hand, one is led to believe that the pessimistic views expressed by others with regard to these problems are grossly exaggerated. It is possible that the peculiar environmental conditions in the tropics far from being, in the physiological reactions they produce, a check to white migration, may in themselves even carry factors conducive to racial betterment. The locality [chosen for the investigations] was well-nigh ideal for the purpose in view. Townsville, situated 19 degrees south on the coastal belt of the Australian tropics, occupies an unique position, being the largest tropical community on the earth inhabited by a pure white race, an almost homogeneous transplantation of Anglo-Saxon and Celtic stock. Besides, this population is a working one, even the most menial occupations being in the hands of whites. Since in any study bearing on the physiology of a populace the frequency of disease is of utmost importance, and since this especially applies to tropical climates, because of the occurrence in man of often unrecognized internal parasites, it should be mentioned that Townsville in this respect is extremely fortunate. I have been informed that for a long period of time no cases of malaria that were diagnosed in Townsville had been infected in that locality. Members of the "hookworm campaign" were stationed in Townsville, at the time of the investigation, and their thorough survey of intestinal parasites contributed also to remove any suspicion that might be entertained that, at least in those town wards and in the boarding school where most of my subjects lived, the health conditions were not satisfactory. The climate of Townsville is a typical monsoonal one. The rainfall, being limited to the hot season, does not, however, as a rule exceed 50 inches during the year. In spite of this the humidity, especially from December to February, is very high, averaging 75 per cent. The monthly averages of the dry bulb temperature vary between 20°C in the coolest month and 28° in the hottest, the average range for the wet bulb temperature is 17° to 25°C. While thus the meteorological conditions for a short period of the year do not seem to come up to the requirements expected in the tropics, it will be remembered that the chemical activity of the insolation during this season in Townsville figures among the highest on record. Although, therefore, the climate cannot be compared with an equatorial climate, I believe that it is fairly well representative of the climate in wide expanses of tropical countries, the suitability of which for white colonization is under debate. For investigating the cooling power of the atmosphere at Townsville the author used the kata-thermometer of Leonard Hill. The reader will recall that by applying the factor for the particular instrument to the time taken for the thermometer reading to decline from 100° F. to 95° F. (after heating in warm water) one obtains a figure that represents the loss of heat from the glass surface in millicalories per cm' per second. Heat loss by conduction is indicated by the dry kata (that is, with the bulb dry and not covered); heat loss by evaporation is shown by the wet kata (bulb covered with wet gauze). As an indicator of the suitability of atmospheric conditions for human beings Hill has shown that for the dry kata: (a) It loses heat about four times as fast as the clothed human body in the same atmospheric environment; (b) a reading of 5 is the minimum requirement for a man doing sedentary work; (c) a reading of 3 is sufficient for a person asleep; (d) a reading of at least 10 is necessary for a man doing muscular work. For the wet kata (quoting Sundstroem) "we may accept Hill's pronouncement that a reading of 12 constitutes a reading below which the body is able to dissipate its heat only by resorting to visible perspiration. These standards are important and should be consulted in connection with the tropical investigations reported below." Departure of the author from the tropics curtailed the contemplated extensive program of observations of cooling power. The conclusions are therefore offered, with full recognition of the scantiness of the data, on the basis of 55 observations. Half of these observations were performed in the building of the Tropical Institute, where for two periods of time, one in the hot season and the other in cooler weather, the cooling power offered by a laboratory room on the second floor was compared with the outside open verandah. The room investigated was in the summer on the lee side, but the verandah received in the cooler season a fairly good breeze. The other half of the observational work was conducted in a house which was located on a hill slope with its front side exposed to the prevailing winds, and which consisted of open front verandah (house screening is not practiced in North Queensland, probably because it is thought to shut off the breeze), sitting room, two bedrooms in the middle of the house, and dining verandah and kitchen in the rear. Although the construction of this house left several things to be desired, it can be taken as a fair representative of the best housing conditions in North Queensland. This applies also to the kitchen, which in this part of the tropics generally lacks a ceiling, and therefore is usually abominably hot, due to the absorption of the solar radiation by the sheet iron roof. The experiments on the cooling power in this house were performed in December and January, consequently in the middle of the hot season, mostly in the afternoon. In addition it was deemed instructive to determine the hindrance to an efficient body cooling that might accompany the use of mosquito nets. In each experiment all the windows in the house were left open and no fire was burning in the kitchen. Cooling power measurements in a laboratory room and on the Following the completion of the major part of the paper here dealt with, Dr. Sundstroem experimented on the physiological reactions of rats to artificially produced "tropical" climates. He found their physiological responses strikingly similar to those of his human subjects in the real tropical climate at Townsville. The strength of this similarity he holds to be a confirmation of his earlier expressed views that it is indeed the decrease of cooling power which in a tropical climate constitutes the primary factor in producing the physiological response. D have been received, one by Mr. Mitchell, from which the first extract below is taken, the other in response to a request by the editor of the BULLETIN for comments on the Miami Hurricane and upon that which grazed southeast Florida on October 20th. This latter storm, it will be remembered, first devastated the Isle of Pines, next did immense damage to Havana, and after providentially missing the Florida mainland gave Bermuda the severest treatment she has received in many years. It may be of interest to you to know that Homestead, twenty-eight miles south of Miami, apparently marked the outer perimeter of the center of the storm of September 18th. The lull here was of only five minutes' duration and would hardly have been noticeable to one not on the lookout for it, or to one not watching a barometer for minimum reading. I have not discussed the matter with Mr. Gray, Local Observer at Miami, but from numerous other inquiries as to the length of duration of the lull, this period apparently reached a maximum near Coconut Grove or Larkins, six to eight miles south of the business center of Miami, indicating a radius of center slightly over twenty miles. This would give a somewhat smaller diameter than the center of the hurricanes of 1909 and 1910. At the time of the 1909 storm I happened to be at the point of greatest diameter at Marathon on the Florida Keys where we had a lull of one hour and fifteen minutes and a minimum barometer of 28.12. My observation of the wind velocity of the 1909 storm, however, was that it was fully as great as that reached this year, though we had no accurate record after our anemometer cups blew off at 110 miles. In 1910 I was within the central area, but not at the point of greatest diameter. Since writing Mr. Mitchell on October 18th I have had opportunity to visit the section in the vicinity of Fort Lauderdale, Dania and Hollywood and was impressed with the fact that the damage along the right forefront of the storm center was greater than in any other quadrant. This I believe confirms similar observations along the paths of other hurricanes. It is also obvious that points situated near the perimeter of the center of such a storm suffer more heavily than those near the full diameter. In the latter case the heavy wind velocities are from practically the two opposite directions only, while points near the perimeter have velocities nearly or quite as great and must withstand wind pressure slowly shifting through nearly 180 degrees. The hurricane which passed to the eastward of this section on October 20th produced a maximum wind velocity of about 70 miles per hour and would ordinarily have caused no great damage. In this instance however a large proportion of the fruit trees which had been reset after the hurricane of September 18th were again blown over, and as the wind direction in the second storm was nearly opposite to that in the first, the damage to the root systems was made so nearly complete that in many cases salvage was no longer possible. INDICATED SEASONAL RAINFALL IN SOUTHERN CALIFORNIA By GEORGE F. MCEWEN "The average of the observed seasonal rainfall at six selected stations from San Diego to Los Angeles for the ten-year period, 1916-1926, was 12.0 inches. The average ocean surface temperature at the Scripps Institution pier, La Jolla, for the interval August 1 to October 15, 1926, was 67.4 degrees. |