Thick Fog Research Articles

A Variety of Hypnotic Techniques

A number of hypnotic techniques of an oriental type with round domes. are described to enable other workers The operator mentioned that bells in hypnosis to facilitate and increase were ringing in a tall steeple which the effectiveness of their hypnotic would soon be under the carpet. The work. These techniques preferably suggested auditory hallucination reinshould not be adopted literally, but forced the fantasy and the trance. modifications and elaborations of them A suggestion for deepening suemay be found to be useful and helpful. cessive trance states: It is important to Precautions for the operator are question the subject concerning his resuggested regarding the advantages of actions and discover what he regards the avoidance of interference with the as important and effective. A number subjects’ individual development of of techniques were used on a subject suggested ideas and procedures, but it simultaneously; among them were eye is also suggested that when this inadfixation on a bright spot, relaxation vertentb occurs, the hypnotist then suggestions, right arm levitation, and can recover the situation by utilizing hyperventilation with suggestion of the unintentional interference to faciltrance-deepening with each successive itate the desired results. breath. After a trance developed, a 1. For rapid deepening of a hypnotic SUCCeSSiOn Of different techniques Was trance state, a technique of especial then to it. value with children: With the subject Questioning of the subject later rein a light to medium trance, he is asked vealed an item, which Was least SUSto feel or to imagine himself to be in Petted by the operator as of value, as some other place he would enjoy, and impressing the subject most Profoundto do this without regard for time and ly. When the subject had first been space. The subject usually goes immeasked to look at the bright spot, it was diately to a world of fantasy. The opsuggested ‘‘Perhaps everything around erator may then reinforce the subject’s the shining spot will become blurred.” fantasy by leading suggestions, taking She commented, “I am a practical, macare to allow the subject to establish terialistic Woman. 1 know that I am the development of the fantasy, which looking in a certain direction and that the operator merely reinforces. there is no reason for part of the image A boy found himself in fantasy flyto become blurred, as if it were hidden ing in an airplane en route to New by thick fog, and yet it happened.” york, sitting next to a man, whom he She continued to marvel over this com-

Letters of Homer Crane Blake Concerning His Naval Expedition to China, Japan and Korea: 1869-1872 (2)

[p. 171] The U.S. fleet in Eastern Waters under the command of Rr. Admiral Rodgers, U.S. Navy, left Nagasaki on May 16th 1871 and anchored off the Ferrieres Is., a small group of islands off the coast on the 20th of the same month. But owing to the foggy state of the weather were unable to proceed to Eugenie Is. until May 23rd. On the morning of the 24th May a surveying party consisting of the Palos and four Steam Launches, all under the command of Commander Homer C. Blake, was dispatched up the Salee River. Soundings were made of the channel, neighboring waters, etc. without molestation from the natives and on the 28th May the surveying party returned to the Fleet off Eugenie Is. During the absence of this expedition the vessels left in Roze Roads had been conducting a series of soundings and several parties who landed held communication with the natives who appeared to be of a friendly disposition. To one of these parties a paper inscribed with Chinese characters was given containing inquiries as to the nature and intentions of the fleet. As the paper was without signature or indication of an official character our informal reply was returned by Minister Low in reply stating that they were Americans, their intention friendly, and that they had come to seek an interview with the governing authorities. A thick fog prevented the starting of the fleet on the next

Coloured Light for Motor-Car Headlights

As many motorists use headlights giving coloured lights, an authoritative and scientific statement as to whether coloured light is better than white light for night driving or during fog has for long been desired. A report by an illumination committee of the Department of Scientific and Industrial Research (Technical Paper No. 20. London: H.M. Stationery Office) has now practically settled the question. Adequate evidence is given that in conditions of slight or thick fog the range of visibility of objects seen in the beam of the headlight is not increased by the use of coloured light obtained from the original white light by means of a filter. One investigator has put on record that in clear weather the range of visibility of an object is increased about 6 per cent by the use of a yellow filter. This result was obtained at a distance of about 900 feet ; but at shorter distances, at which the motorist is more concerned to see objects, the advantage of the yellow filter, in any event small, is still smaller. There is experimental evidence that the power of the to perceive contrasts of brightness in the presence of a dazzling light is enhanced if similar colour filters are placed over the dazzling light and over the light illuminating the objects viewed. The evidence as to whether the use of coloured light obtained from white light by means of a coloured filter enables the eye to detect contrasts of brightness easily is conflicting. Recent investigations have shown that there is a slight advantage, but this is meonsistent with the measurements of earlier workers. There is evidence for a slight increase in the power of the eye to perceive the details of a pattern in black and white' by the use of yellow light obtained from white light by means of a filter.

Fog

Among the various applications of meteorology to the practical requirements of everyday life, the observation of fog, as a meteorological element, has. been associated primarily, in the past, with locomotion on land and with navigation on the sea. The first scale of fog intensity used by meteorological observers in this country was, in fact, based on the effect of different degrees of atmospheric obscurity on navigation. The scale was drawn up in 1903 as the result of an investigation into the conditions of formation of London fogs, and subsequently modified by the Meteorological Office, in conjunction with the Admiralty and Trinity House (see Table I.). It included five specifications of fog intensity ranging from a clear atmosphere free from fog or mist, represented by “ of,” to a thick fog, denoted by “ sf.”Within the last twelve years, while the importance of fog as an obstruction to road and rail transport and to shipping has in no way diminished, the reporting and forecasting of fog has assumed a new significance in relation to air navigation.

Atmospheric pollution and potential gradient at Kew observatory, 1921 and 1922

1. It has long been known that fog at Kew Observatory is usually associated with high values of the potential gradient of atmospheric electricity, and it was found some years ago that the influence was not confined to thick fog, but prevailed to a greater or less extent in less opaque conditions of the atmosphere, diminishing as the opacity diminished. The introduction of one of Dr. Owens' pollution recorders has enabled a more complete investigation to be made of the influence of impurity of the atmosphere on the potential gradient. The pollution and potential records for two complete years, 1921 and 1922, are utilised. Before proceeding further, a reference is necessary to the nature of the pollution records. The amount of impurity is determined by the blackening of a paper filter, through which a definite volume of atmospheric air has been drawn. The blackened area is compared optically with standard papers, and a pollution number 0, 1, 2, etc., is assigned accordingly. Two points call for particular notice. There is necessarily a considerable interval of pollution covered by any one pollution number, and in particular No. 0 does not really mean a total absence of pollution. The second point is that the assumption that a given darkening of the biter paper answers to a definite mass of dirt per unit volume of the atmosphere may be only an approximation to the truth. Conceivably, some dirt may, mass for mass, blacken the biter paper less than other dirt. The composition of the dirt in the atmosphere may vary throughout the year. There may, for instance, be differences in the sizes of dust particles, and the influence on the potential gradient may depend on the average size of the particle, as well as on the dirt mass per cubic metre. minute knowledge of the composition of the dust may be essential to a complete study of its action. On the other hand, as will appear presently, the effect is not a small one, and it has appeared desirable to publish the results obtained without further delay.

Electric potential gradient and atmospheric opacity at Kew Observatory

It has long been known at Kew Observatory that thick fog is generally accompanied by a high value of the electrical potential gradient. During fog the oscillations of potential, which are common even in the electrically quietest of days, are sometimes very large; but whether they are exceptionally large, when expressed as a percentage of the mean gradient for the hour, has not been investigated. There is this peculiarity, however, that sometimes during fog the gradient oscillates between a positive and a negative value, a phenomenon which is quite exceptional except during rain or a thunderstorm. It occurred to me to examine the records for a series of years to see whether any information could be derived as to the existence or formation of fog. The appearance of the electrogram during heavy fog is usually so characteristic that from it alone one could say with a close approach to certainty that fog existed. Thus electrograms may be of considerable value as confirmatory evidence of fog when direct evidence is lacking. But the influence of light fog or mist does not seem sufficiently regular and dominant to encourage the hope that potential gradient curves by themselves can serve satisfactorily as a prognostic of fog.

Atmospheric Electricity and Fog

IN view of the interest recently shown in the subject of the dispersion or prevention of fog, it may be opportune to direct attention to a recent remarkable example of an atmospheric electricity phenomenon which usually accompanies London fogs. I should first explain that the method adopted at Kew for determining the absolute value of the potential gradient—i.e. the increase in the voltage per metre of height above the ground—certainly does not err in the direction of overestimating it. Taking eight years, 1898 to 1904, I found in a recent paper1 that the mean value of the potential gradient at Kew was 159, the mean value for January being 201. The phenomenon referred to above is the occurrence during fog of specially high positive potentials, values double or treble that appropriate to the season being not unusual. At such times, however, there are usually large and frequent oscillations in the value of the gradient, so that the maintenance of an exceptionally high value for a number of consecutive hours is comparatively rare. On the morning, however, of January 21, during an intensely thick fog, the potential, gradient at Kew exceeded 730 continuously from 1 to 9.30 a.m. How much it may have exceeded this value it is impossible to say, as the trace was beyond the limits of registration during the whole of this time. Both before the trace left the sheet and after its return the oscillations in the potential gradient were large, so that the maximum value was probably at least 1000.

Condensation Nuclei 1

A FAMILIAR experiment was first shown illustrating the action of ordinary dust particles as condensation nuclei. From a large globe, which had been allowed to stand for some hours, some of the air was removed by opening communication with an exhausted vessel. Only a very few drops were formed as a result of the expansion. On allowing air to enter the globe through a cotton-wool filter, so that the pressure was brought back to its original value (that of the atmosphere), and allowing the air to expand as before, the drops formed were again very few. The ordinary air of the room was now admitted; an expansion of the air in this case resulted in the production of a thick fog.

The Recent Magnetic Storm and Aurora

A most splendid and beautiful aurora borealis was visible for a long time yesterday evening, October 2 in this town, commencing at 6h. 40m. The weather had been precarious all day. In the early morning there was a thick white fog, the wind being south-west. The wind afterwards changed from that point to the north-east, then in the afternoon to the north. The sky had been much overcast, and some slight showers of rain fell at intervals. The wind then suddenly changed to the west, for a short time, and then back to the north, gently driving the clouds away to the south-east. The aurora then became visible, and was most gorgeous and brilliant, throwing up incessantly various coloured streamers, and many flashes of white light, which passed several degrees beyond the zenith. When the moon arose shortly after 9 p.m. the appearance was still in existence, and was very singular and impressive. During the display and until the aurora had finally disappeared, two large white clouds or nodes were visible, one being similar to a large lump, and the other streaming, and of great brilliancy, in the opposite direction, and they continued so for some time after the aurora had finally disappeared.

III. On dry fog

It has often been noticed, especially in and near large towns, that a foggy atmosphere is not always saturated with moisture : thus on the 17th of October last, at 3·30 p.m., during a thick fog in London, the degree of humidity was only 80 per cent, of saturation; and Mr. Glaisher, in his memorable balloon ascents, observed that in passing through cloud or fog the hygrometer sometimes showed the air to possess considerable dryness. In the ascent from Wolverampton, on July 17, 1862, at an altitude of 9,882 feet, and when passing through, a cloud so dense that the balloon could not be seen on the car, the dry bulb thermometer read 37°·8 F. and the wet ;0·°2, indicating a dew point 17°·9 below the air temperature.

Lunar Ring

WHILE experimenting on the actenic power of lunar light on August 30 last (period of full moon), at 9.30 P.M., I obtained, with a minute-and-a-half exposure, a photographic negative of the moon, which shows a distinct and well-defined ring or glory around it which was not visible to the naked eye on looking directly at the moon in a clear and cloudless sky, nor was there any halo on the ground glass of the camera, nor on the lens, at the time of observation This is a copy of it from the negative. I used no clock-work arrangement with the camera, but allowed the moon to traverse the plate, and I have since then taken several photographic observations under various conditions. I have taken the moon in all her phases, with long and short exposures, in clear and cloudless sky, and never could get a ring even faintly defined. I have also heated the camera and screwed the cold lens into it, carried it into a colder atmosphere in order to produce condensation of dew. I have placed two small separate openings in front of the lens; on one occasion I dusted puff-ball spores upon the lens; on another I breathed warm breath upon it, but never got anything but decided burr, which was always densest near the limb of the moon and gradually tapered away towards the circumference like a bright light seen through a thick fog, but no appearance of ring. I have also taken observations when scud was passing rapidly over the moon, when perfect prismatic halos were visible to the naked eye, but no ring was ever impressed on the photographs; nothing more than a haze, such as that produced by breathing on the lens. The next full moon (September 29) was totally obscured, so that I failed to get an observation then; but last evening (October 29), at 10 P.M., I was fortunate to get one fine, clear exposure of one-and-a-half minute, and was pleased to see a clear and well-defined ring rise up on the plate during development, similar in every respect to that obtained on August 29, showing clearly that this unusual appearance is dependent upon the position of the moon in her orbit, she being in opposition when she manifests ring-giving power and shows us a crown. But why is this? What is the cause of this unusual, and, I believe, hitherto undescribed, appearance? Why should this ring be invisible to the naked eye and yet give a luminous impression on a photographic plate? Why should it appear only at full moon period and not at any other phase? Can it have any connection with what Mr. Newall saw round Mars through his huge telescope? If the moon had an atmosphere similar to that of the earth, and a star of some magnitude were occulted by the moon at that particular time, it is possible that its light in passing through the lunar atmosphere might be refracted so as to show a corona round the moon; but it is pretty generally acknowledged that there is no atmosphere surrounding it, therefore there can be no refraction.

The Swedish North-East Passage Expedition

From letters despatched from the mouth of the Lena by Prof. Nordenskjöld on August 27, which have just been published in the Gothenburg Handels Tidning, we learn that the Vega accompanied by the Lena left Dickson Harbour, at the mouth of the Yenissej, on August 10, the weather being fine. On the 11th ice was seen, but it consisted almost exclusively of bay ice which did not obstruct navigation, which, however, was rendered difficult by a thick fog. The salinity of the water began gradually to increase and its temperature to fall. Organic life at the bottom grew richer at the same time, so that Dr. Stuxberg on the night between August 13 and 14, while the vessel lay anchored to a drift-ice floe, collected with the swab a large number of beautiful pure marine types; for example, large specimens of the remarkable crinoid, Alecto eschrichtii, numerous asterids (Asterias linckii and panopla) pycnogonids, &c. The dredgings near the land now too began to yield to Dr. Kjellman several large marine algæ. On the other hand the higher plant and animal life on land was still so poor that the coast here forms a complete desert in comparison with the rocky shores of Spitzbergen or West Novaya Zemlya. Auks, rotges, loons, and terns, which are met with on Spitzbergen in thousands upon thousands, are here almost completely absent. Gulls and Lestris which there fill the air with continual sound occur here only sparingly, each with two species, and it appears as if they quarrelled less with one another. Only the snow-bunting, six or seven species of waders, and a few varieties of geese are found on land in any great numbers. If we add a ptarmigan or two, a snowy owl, and a species of falcon, we have enumerated the whole bird fauna of the region, at least so far as the Swedish expedition have been able to ascertain it. Of warm-blooded animals in the neighbouring sea, only two walruses and some seals, Phoca barbata and hispida, were met with. There is probably great abundance of fish. Cosmic dust was sought for on the ice without success, but there was found upon it some yellow specks which, on examination, were found to be a coarsegrained sand, consisting exclusively of very beautifully-formed crystals up to two millimetres in diameter. The nature of these crystals was not ascertained, but it was evident that they are not formed of any ordinary terrestrial mineral, but possibly of some substance crystallised out of the sea-water during the severe cold of winter.

The British Association

LIVERPOOL, Wednesday THE number of tickets issued has now increased to 2,800, very considerably more than was expected either by the officers of the Association or by the Liver-pudlians. The roll of eminent foreigners is also much larger. In addition to those mentioned in my first letter we have now the company of Prof. Tchebichef, of St. Petersburg, one of the most distinguished of living mathematicians, Prof. Plateau of Bruges, Dr. Anton Dohrn of Jena, Prof. Von Baumhauer of Leyden, and others. Some of these have added greatly to the interest of the sections in which they took part, and have been very warmly received. Dr. Dohrn in particular was greeted with much warmth, from the fact that three weeks ago he was summoned to join the German army and had not since been heard of by his English friends. The statement of a local paper that Prof. Hofmann of Berlin is here is incorrect. A letter was, however, read from him in the Chemical section, soliciting contributions in kind from our chemical manufacturers for the needs of the German hospital service. A large audience met to-day in the Geographical section to hear Lord Milton read his paper on “Railway Routes across America;” and the lecture-room in which the Ethnological sub-section holds its meetings was crammed whilst Sir John Lubbock was discoursing on “Stone Implements from Western Africa.” The small and inconvenient Crown Court in St. George's Hall devoted to Section A had a much larger complement than usual while the Rev. F. Hewlett read his paper on “Solar Spots,” and exhibited his elaborate diagrams, showing the great interest now taken by the public in solar phenomena; although, at the same time, Section G offered a counter attraction, especially to the members connected with the town, in Mr. Mackie's and Sir E. Belcher's papers on “The Unprotected State of Liver-pool. ”The heavy rain and thick fog of yesterday morning have both cleared off, and the weather is again everything that could be desired.