IRLF 
 
 37D 
 
GIFT OF 
 
 8061' 12 
 
LATEST ADVANCES IN WEATHER FORECAST 
 
 ING AT A LONG RANGE BY SUNSPOTS 
 
 AND PLANETARY POSITIONS 
 
 JEROME S. RICARD, S. J. 
 
 Reprinted from Popular Astronomy, Vol. XXl^ No. 3 
 March, 1913 
 
LATEST ADVANCES IN WEATHER FORECASTING 
 
 AT A LONG RANGE BY SUNSPOTS AND 
 
 PLANETARY POSITIONS. 
 
 JEROME S. RICARD, S. J. 
 
 The sunspot is not yet fully understood, nor is meteorology, nor 
 planetary influence, nor electromagnetism. However much we may 
 imagine we know about these subjects, no well-trained mind can deny 
 that much more remains to be learned. Hence we do not feel disposed 
 to agree with those who say these fields have been investigated and 
 found wanting so much that our knowledge of the causes of phenomena 
 remains in the statu quo of the old ignorance. Much more is now 
 known of the sunspot than, say, ten years ago, thanks to Dr. Hale of 
 Mt. Wilson and his devoted and learned staff, not to mention others in 
 and out of the United States. Meteorology, too, has advanced to a 
 knowledge of causes undreamt of before, and our wireless systems of 
 telegraphy have opened new avenues of indefinite progress. Planetary 
 influence on both sun and earth has been subjected to rigid tests and 
 marvelous results have been obtained. 
 
 Hence it were but little surprise if at no distant date, there were a 
 complete turning of tables. The very men, who had been, as it were, 
 relegated to an obscure corner and belittled as aspirants to scientific 
 treasures beyond reach, will be the very ones that a grateful posterity 
 will hail as benefactors of the race. We have special reference to 
 such "painstaking students of nature as have spent from ten to fifty 
 years of their useful lives in tracing the complicated phenomena of 
 astronomy, meteorology, seismology and biology to their proximate and 
 ultimate causes, and yet have been so modest as to avoid self-assertion 
 and even publicity during the experimental period of their proceedings. 
 Not only is the sunspot now better known in itself, but also in its 
 relation to aero-physics, the jealous department where every man is 
 wiser than his neighbor and the mixed up total of individual wisdoms, 
 if only photographed, might be exhibited as the picture of general 
 unknowableness. The modest quota contributed by the Santa Clara 
 Observatory may be described as follows: 
 
 As long as the period of maximum frequency of sunspots lasted, a 
 desire for simplicity of view and result dictated that we should confine 
 ourselves to a study of the western limb, which had at first attracted 
 
 * Director of the Observatory, University of Santa Clara, California. 
 
 267000 
 
Latest Advances in. Weather Forecasting 
 
 our attention as the scene of coincidences between disturbances on the 
 sun and disturbances on the earth. As a result of a simple but very 
 direct investigation, which we have carried on uninterruptedly since the 
 year 1900, when an 8-inch equatorial was installed, the 3-day law concern- 
 ing the western limb was found to hold generally and in consequence we 
 published it. Of this article in POPULAR ASTRONOMY April 1911, 1100 
 copies were ordered by W. T. Foster of Washington for free distribution 
 among friends, including astronomers and meteorologists of note, 
 and a translation into French was made by Jean Mascart then of 
 the Observatory of Paris, now Director of the Observatory of Lyons. 
 
 At that epoch of our pioneering, it sounded passing strange that the 
 western limb should thus appear to be in direct communication with 
 the western coast of the United States in preference to any other coast 
 that we had knowledge of. And it was only natural that certain 
 reflecting minds should put in a demurrer to what they called a theory, 
 and we called a fact of observation, which we could not explain and 
 did not care to explain so long as the fact stood. Meanwhile time went 
 on and, to our great discomfort, the period of minimum frequency set 
 in. We had been using the 3-day law, had tested it in every kind of 
 way by issuing forecasts which, all in all, held for semi-monthly periods. 
 
 But during this time of minimum frequency there were not, except 
 very seldom, any visible spots that we could with any degree of certainty 
 locate as having to be at some future time, within three days dist- 
 ance from the western limb. Sometimes there were no spots at all; at 
 other times, they were mere vanishing apparitions and so, on the whole, 
 it looked as a complete denudation of the solar surface. And yet we 
 sorely wanted some sort of sun trouble in order to forecast disturbances 
 on the earth. Past observation came to our rescue; we had often 
 noticed that faculae could be fairly well descried on the eastern limb, 
 which on the way across, became lost in the effulgence of central light 
 and finally recovered visibility within 45 or 50 from the western 
 limb. We had noticed, too, as had other observers often before, that 
 the so-called dark spots underwent every kind of change in the midst of 
 facular fields. They would leap into view suddenly; become drowned 
 the next day; and then float again the following day. Witness the little 
 spot in the faculae of October 20, 1912. 
 
 We therefore arrived at the conclusion that a solar disturbance, once 
 started, would continue until it was supplanted by a new one, or until 
 it got a new lease of life from a new cause that came into play, thus 
 making the old focus of disturbance the seat of the new one. Nodon 
 of the astronomical society of Bordeaux had noticed the same thing. 
 However it would cost nothing to experiment, and note the results and 
 observe what help it might bring to the forecaster. 
 
Jerome S. Ricard, S. J. 
 
 The experiment has so far proved a great success, the reality having 
 always corresponded to anticipation and this not only with regard to 
 the western limb, but the eastern limb also and the central meridian 
 both in front and in back. By this new discovery the task of forecasting 
 earth's weather by the sun's weather, if the expression be allowed, 
 becomes mere child's play and the weatherman can plunge as deeply 
 into the future as prudence may dictate. There will always be difficulties 
 from new disturbances on the sun, which might occur so far out of place 
 as to upset the previous calculations. Hitherto our limit of forecasting 
 has been one month, during which, and especially at the end of which, 
 failure or success is carefully ascertained from the weather map. If 
 any slips have occurred, an investigation immediately follows and it 
 shows constantly that one solar disturbance had been overlooked or 
 another had set in out of harmony with the one or the ones that had 
 been used as bases of calculation. But what is worthy of note in this 
 connection, is that a recalculation, by the 3-day law applied universally, 
 based on the omitted spot or the new one, brings a result that is entirely 
 in harmony with the dates of the real meteorological events of the past 
 month. 
 
 AN ISOMETRIC PROJECTION OF THE SUN 
 
 Showing the group of August 8, 1910 in front and back, illustrating the 
 method of forecasting siesmic and meteorological disturbances by the 
 experimental theory of position. (Courtesy of Dr. A. Porta, associate 
 observer, University of Santa Clara, Calif.) 
 
Latest Advances in Weather Forecasting 
 
 To put the whole process in a nutshell: Observe the sun. If you see 
 a spot or a facula, find its heliographic latitude and longitude, taking 
 Central Meridian as the zero line. Roughly speaking, a spot takes twelve 
 and one half days to go from limb to limb in front and a little over 
 fourteen days from limb to limb in back (Synodic period). Or, 
 to state the fact more pointedly, it takes six and one fourth days 
 from eastern limb to Central Meridian on this side, six and one fourth 
 more days from Central Meridian on this side to western limb, then 
 seven days from the western limb to Central Meridian on the other side 
 and finally seven more days from there back to eastern limb, traveling 
 at the rate of 14.4 degrees a day. The longitude of the spot converted into 
 days and combined with its rate of motion will tell at once what day 
 of the month the spot will be three days distant from Central Meridian 
 this side or that and from both limbs. The dates thus obtained may be 
 set down for the appearance of new areas of low pressure, or storms, on 
 the westernmost part of the Pacific Slope, Washington, Oregon, California, 
 Arizona. Further investigation of the most delicate kind, promises to 
 show how the observed latitude of the spot may be utilized for telling 
 approximately where the storm will strike. 
 
 A few examples, not imaginary, but of actual observation, will make 
 the calculation of stormy periods clear. 
 
 EXAMPLE I. 
 
 On Oct. 17, 1912, a facula stood one day in. Hence it stood on 
 
 Central front Oct. 22^4 
 
 Westernlimb " 2SV 2 
 
 Central back Nov. 4V2 
 
 Eastern limb ll 1 /^ 
 
 Central front " * 1794 
 
 Westernlimb " 24 
 
 Central back Dec. 1 
 
 Eastern limb " 8 
 
 Subtracting 3 from each one of these dates, we get the following 
 stormy periods for this coast: 
 
 Oct. 19V4 to 22V4 
 
 " 25V2 to 28V2 
 
 Nov. 1V2 to 4V2 
 
 8V 2 to 11V 2 
 
 14% to 17% 
 
 " 21 to 24 
 
 28 to Dec. 1 
 Dec. 5 to 8 
 
Jerome S. Ricard, S. J. 
 
 EXAMPLE II. 
 On Oct. 20, another facula was \ l /2 days in. We have therefore: 
 
 Central front ............ Oct. 24% 
 
 Western limb ............ " 31 
 
 Central back ............ Nov. 7 
 
 Eastern limb ............ 14 
 
 Central front ............ " 20 1 /4 
 
 Western limb ............ " 26 1 /2 
 
 Central back ............ Dec. 3V2 
 
 Eastern limb ............ " 10V2 
 
 Proceeding as in Ex. I, we get the following stormy periods: 
 
 Oct. 21% to 24% 
 
 " 28 to 31 
 
 Nov. 4 to 7 
 
 " 11 to 14 
 
 " m/4 to 20^4 
 
 " 23V 2 to 26V2 
 
 " 30V2 to Dec. 3V 2 
 
 Dec. 7V2 to 10V 2 
 
 EXAMPLE II. 
 
 Also on Oct. 17, the facula of Oct. 14 stood \Vi days from western 
 limb. Hence: 
 
 Western limb ............ Oct. 18V 
 
 Central back ............ " 25M? 
 
 Eastern limb ............ Nov. l l /2 
 
 Central front ............ " 7% 
 
 Western limb ............ 14 
 
 Central back ............ " 21 
 
 Eastern limb ........... . " 28 
 
 Central front .......... .. Dec. 4^4 
 
 Western limb ....... ..... " 
 
 Operating as above we have for the stormy periods: 
 Oct. 22V2 to 25V 2 
 
 " 29 V2 to Nov. V/2 
 Nov. 4% to 7% 
 " 11 to 14 
 " 18 to 21 
 41 25 to 28 
 Dec. 1V4 to 4V4 
 8 to 11V4 
 
6 Latest Advances in Weather Forecasting 
 
 In examples II and III, the faculae stand in such favorable positions 
 that the results sensibly agree. Example I stands for separate storms. 
 Accordingly in our forecast for November published on October 30, 
 prominence is given to the periods based on faculae of October 14 and 
 20, while attention is also called to November 1, 8, 14, 21, 28, December 
 5, for either the augmenting of already extant warm waves or the 
 approach of new ones, as per example I. A magnificent verification is 
 just now going on, this being November 5, 1912. If there was only one 
 facula or spot doing service for twenty-seven days, there would be only 
 four storms during that time. But if there were several, either they 
 would happen in critical positions or not; in the first case, the storms 
 would coincide and intensify each other both in depth and area; in the 
 second, they would be separate and one follow on the heels of the 
 other at distances of 1, 2, 3 days. * 
 
 * The forecasts of Ex. I, II, III were from 30 to 40 days in advance. They were 
 a strange novelty to us, requiring careful combination and segregation. The oppor- 
 tunity was thereby offered of making a rare test and the result has been watched 
 with anxious care. At the present date, January 22, 1913, in compliance with a 
 request from POPULAR ASTRONOMY, we append, in parallel columns, first, a list of the 
 real storms, as found in the official weather chart of the U. S., which occurred from 
 October 19 to December 5, 1912, and, second, a list of dates announced from mere 
 solar observation covering the same period, The agreement between reality and 
 prognostication appears to be so exact that the error if any is either negligible or 
 explicable. It all seems a great triumph for sunspots and likewise for planetary 
 meteorology, since the planets are successfully used in getting the same dates quite 
 independently and also in forecasting solar disturbances. 
 
 EXAMPLES I, II, III, COMBINED AND ORDERED. 
 The Weather Map By Sunspots 
 
 Oct. 19 - 23 Oct. 19 - 22 
 
 " 24-26 25-28 
 
 " 28-30 - 28-31 
 
 Nov. 1 - 3 Nov. 1 - 4 
 
 "5-7 4-7 
 
 "8-9 -8-11 
 
 " H-15 11-14 
 
 " 18-20 18-21 
 
 " 20-21 21-24 
 
 " 25 - 27 25 - 28 
 
 " 27 - 28 28 - Dec. 1 
 
 " 28 - Dec. 3V 2 " 30 - Dec. 3 
 
 Dec. 5-8 Bee. 5^8 
 The above cannot be mere coincidence, far less guesswork. 
 
Jerome S. Ricard, S. J. 
 
 The result of the new experience briefly amounts to this: 
 
 There are in all four critical positions: three days before the spot 
 reaches the western limb; three days before the spot reaches the Central 
 Meridian in back; three days before the spot reaches the eastern limb; 
 three days before the spot reaches the Central Meridian in front. 
 We mean to say that when a solar disturbance reaches any one of 
 these four positions, a new storm arrives on the Pacific Coast, either 
 rising from the ocean directly or descending from Alaska or ascending 
 from the mouth of the Colorado in Baja California. 
 
 The anomaly of Western limb being alone responsible for storms on 
 this Coast and thence over the whole or part of the United States, is 
 thus removed and we have instead one harmonious whole governed by 
 the three-day law. This great fact is the solid foundation on which 
 rests the claim, made by a respectable number of serious scientists, that 
 the connecting link the causa intermedia between sun and planets 
 is electromagnetism, which, while knowing no distinction between front 
 and back, has its own peculiar laws of action that set at naught the 
 views of the uninitiated. With a view to remove a number of well- 
 meant difficulties, we beg leave to offer the following remarks: 
 
 The idea that a sunspot is a cosmic cause, the effect of which, if any, 
 must be equally distributed throughout the whole earth, is adhered to 
 with the greatest tenacity. It is, as it were, the rostrum from which 
 certain otherwise very estimable writers deliver their elegant sentences 
 to the admiring throng beneath. Otherwise stated the principle is this: 
 the sunspot is a universal cause; therefore its effect, if any, mast be 
 universal. Hence if it causes magnetic storms, earthquakes, aurorae 
 atmospheric upheavals, these have to cover the whole earth. But 
 as they never do so, the inevitable conclusion follows that it has 
 nothing to do with them. 
 
 How this idea got to be so wide-spread and deep-rooted is hard to 
 understand. Possibly it may have arisen as certain other popular errors, 
 now condemned by science, have arisen; viz, we generally believe the 
 reports of our senses even in regard to objects which transcend their 
 capacity and we do not pause long enough to apply to them the ordin- 
 ary criteria by which the reason tests the data of experience. We see 
 for instance how the sun sheds its light wherever no obstacle intervenes; 
 we see, too, how the sunspot looks down on the whole earth and then 
 the unwarranted conclusion comes that as the light penetrates every- 
 where, so the sunspot, if at all efficient, must have its effect visible 
 everywhere. Unfortunately this hurried conclusion belongs to the 
 sensible order and deals with an object with regard to which the senses 
 may deceive, and should therefore be distrusted until the reason, after 
 due examination, approves of their decision. It is to be feared that 
 
8 Latest Advances in Weather Forecasting 
 
 otherwise very respectable scientists may not be careful enough to see 
 whether this inference agrees with the findings of scientific observation. 
 They would thus be in danger of accepting it too hastily as an axiom on 
 which to base themselves while discussing the possibility or impossibility 
 of foretelling, not only the weather but also earthquakes, from the 
 presence of sunspots in general or in certain positions. 
 
 While personally we take no special interest in that so-called axiom, 
 since our method of forecasting prescinds from it and depends 
 entirely on the physical basis of observation and has nothing to do with 
 the metaphysics of the case, yet, as we have time and again noticed 
 that certain writers and speakers, whose turn of mind brings them to 
 pay attention to the feeble attempts we have made in forecasting, show 
 an inclination to go much more by that axiom than by the encouraging 
 results so far achieved, we have thought it worth while to dwell some- 
 what upon this matter and offer some helpful reflections that may pave 
 the way to a better understanding. 
 
 First of all, we could direct attention to another and less doubtful 
 axiom, namely that "Whatever is received follows the manner of being 
 of the recipient", which is sufficiently evident in itself and the applica- 
 tion of which presents no difficulty. Thus spoke the schoolmen. In 
 more intelligible language, we might possibly say. "The reception of 
 the influence of a given activity depends very much, sometimes 
 entirely, on the form, nature, situation and disposition of the recipient." 
 In the light of this axiom, even on the admission of the universality 
 of solar causation, sunspots included, it would not follow that the 
 effect must be everywhere and equally distributed on the whole 
 earth, because the receiving subject might not be disposed at 
 all or very differently disposed in different localities. Those who 
 attribute every weather change to purely local influences under the 
 general agency of the sun, fully understand the pertinence and value of 
 this remark: magnetic and electrical conditions, topography, altitude, 
 air distribution, moisture, present temperature, geological conditions, 
 are all different. The axiom is well recognized in physics in the law 
 of cosines for radiant heat and the intensity of light. One has only to 
 
 glance at the formula I = ^ X cosh to see how the reception of solar 
 
 radiation of both heat and light is enormously affected by the distance 
 and the angle of the receiving surface. 
 
 In the above equation,* 
 * Vid. Ganot's Physics, 15th Ed., Art. 421; Young's Gen. Astron. rev. Ed., p. 136. 
 
Jerome S. Ricard, S. J. 
 
 I = intensity of the effect, 
 
 Q amount received, per unit area, 
 
 D = distance of the cause, 
 
 h -= angle between impingent activity and the normal to the 
 
 receiving surface. 
 
 Class-room formulae, however, might be questioned when transferred 
 to the immensely greater laboratory of nature. For instance in Decem- 
 ber the sun is nearly 3,000,000 miles nearer to us than in July. If 
 therefore a thermometer could be properly installed anywhere in our 
 latitudes so that the receiving surface was normal to the incident ray, 
 it would be warmer in December than in July. Of course, the experi- 
 ment has not been tried; but if it were, we feel rather skeptical about 
 the result. At any rate, physical science admits the axiom quoted, 
 and this is sufficient for our purpose. 
 
 Another idea that should claim attention is the fact that if, as is 
 generally done, we suppress altogether any external influence except 
 the general effect of the sun upon the earth, and therefore fall back 
 entirely upon mere local agencies for the formation and advance of 
 storms, one is at a loss to see how particular agencies of a mere local 
 character can account for the transcontinental and even trans-oceanic 
 character of many of our terrestrial storms. For instance, how will you 
 explain that a big storm in the northwest, say west of Alaska, will 
 descend upon the States of Washington, Oregon, California and even 
 Arizona, then cross over the Rocky Mountains, the prairie, the Eastern 
 States, plunge into the Atlantic Ocean and finally invade Western Europe, 
 unless we suppose similar agencies always of a local character are to 
 be found all along the track of the storm-center ? But an alignment 
 of such purely local causes, conspiring to give us a storm of the 
 above-mentioned sort, is not only not likely, but is actually disproved 
 by the daily meteorological observations of the Weather Bureau, taken 
 simultaneously right along the track of all the storms that pass over 
 the United States. The obvious inference is that every storm, far from 
 being originated by local influences or conditions, does itself originate 
 its own conditions and carries them along with it. The next inference 
 would seem to be that a cosmic cause, one altogether foreign or external 
 to the earth, is the parent of our atmospheric disturbances and that, 
 general in character though it may be, there is some other force in the 
 recipient than a mere local affair which defines, particularizes, 
 and localizes the Cosmic force, in spite of any universal character that 
 one may be pleased to endow it with. 
 
 Hence one who reasons is inclined to wonder somewhat at the hasti- 
 ness of those who jump at conclusions regarding matters so complex 
 and so recondite that they have baffled the many efforts of honest and 
 
10 Latest Advances in Weather Forecasting 
 
 laborious scientists of the present and past centuries. But the wonder- 
 ment increases and rises rather high when we see such representatives 
 of science as Professors Lagrange of Belgium, Gockel of Germany and 
 Nordmann of Paris, either openly or covertly, declare that sunspots 
 being a general, universal, cosmic cause, it is futile to appeal to them 
 with a view to account for certain terrestrial phenomena, such as 
 weather and earthquakes, which are always more or less local* 
 
 Relying on the apparently solid basis that a universal cause must 
 needs have a like effect, they gravely tell us that if, by sunspots or 
 what amounts to the same, critical planetary positions, it rains in 
 Portland, Oregon, it should also rain in Santa Clara, Calif. Or if a 
 hurricane rages at Acapulco it must also rage in Cuba and Porto Rico. 
 The conclusion is forced beyond due limit, exaggerated, illogical to a 
 degree, so much so as to constitute a case of non sequitur. We are 
 not aware that any trained meteorologist or habitual observer of the 
 sun in its various aspects, has ever dared go so great a length. 
 
 In the third place, it might be urged that a twelve year experience 
 at this observatory has traced an invariable connection . between sun- 
 spots, dark or brilliant white, with the advent of new storms on the 
 Pacific Coast, and that as these storms are very particular and definite 
 as to depth, area and track it follows that in virtue of the invariable 
 connection just mentioned, either the spots themselves are particular 
 definite causes, or if they are general causes, their influence is defined 
 and particularized by some terrestrial force which is not merely local; 
 or, if it be urged that other storms are simultaneously started in other 
 parts of the world, which a wider experience will no doubt prove to be 
 true, yet each of them is still certainly definite and particular in depth, 
 area and track, and does not cover the whole earth as it is claimed it 
 should, if our conclusions are true. The above is equally cogent if 
 applied to the planets in certain definite positions which are claimed by 
 nearly all philosophical meteorologists to be the simultaneous causes of 
 spots as disturbances on the sun, and of storms on earth as disturbances 
 in our atmosphere. 
 
 Fourthly, the sunspots are great centers of magnetic force, as shown 
 by the most exact and delicate experiments at Pasadena, Calif., and by 
 an entirely different method at this observatory. But the field of a 
 magnet is very different as you pass around from one pole to the other 
 As the earth revolves and rotates in that field, every different part of 
 it must be differently affected. Add to this the magnetism of the earth 
 
 * (Vid Bulletin de la Societe Beige d' Astronomic No. 3, 1910 Scientific Amer- 
 ican Supplement, Aug. 17, 1912. -Le Matin, Paris, Sept. 8, 1912.) 
 
Jerome S. Ric'ard.^S.J. \ \: :' -. ',: >, ' 11 
 
 itself with its poles and equator and the various agonic and isogonic, 
 aclinic and isoclinic lines which will emphasize the difference. Thus, 
 then, the earth and the sun with its spots are two huge magnets and the 
 effects of neither of them single or combined are exactly the same 
 everywhere; rather they exhibit so great and so complex differences as 
 to demand an extension of our present knowledge of mathematics. 
 Now it is well known that the movement of certain metallic substances 
 in a various and varying magnetic field, generates a various and varying 
 electric current, and conversely. It is electromagnetism, to which, in 
 all likelihood, the variations of our weather and seismic phenomena are 
 mostly due, a theory supported by eminent meteorologists of the most 
 modern type and to which we feel greatly inclined as the only one that 
 stands examination and which, it is to be hoped, every succeeding ex- 
 periment will corroborate. 
 
 Thus then the reader can see for himself that the axiom under dis- 
 cussion, that a universal cause has a like effect, in the sense in which 
 certain writers take it when they naively tell us that if, by sun spots it 
 rains in Athens, it must also rain in Constantinople; or, if there is an 
 earthquake in Patagonia, the whole earth must shake, runs amuck with 
 physical science and ignores the facts of electromagnetism as demon- 
 strated by Faraday, Clerk Maxwell and Ampere, not to mention other 
 names of undisputed authority. 
 
 Once more, people seem to forget that the sunspot, dark or brilliant 
 white, has a sidereal period of a little over twenty-five days and a syn- 
 odic period of a little over twenty-seven days and that its effectiveness 
 is as great on the other side of the sun as on this side. This repeated 
 experiment at 1 his observatory has abundantly proved, especially during 
 the present period of least frequency. Once on the field, the activity of 
 a solar disturbance lasts very long, very likely until it is replaced by 
 another or becomes revivified by the activity of some new heliocentric 
 conjunction or opposition, with or without a simultaneous quadrature 
 about the line from Jupiter to Saturn. Further observation will soon 
 furnish a solution of this last mooted point.* 
 
 On the other hand, it should carefully be borne in mind that a large 
 number of real storms, especially during the summer of a given locality 
 or country, will pass through altogether unnoticed: invisibly they are 
 mighty oscillations of the barometric curve, and sensibly only a hot 
 wave. There are no clouds, very little wind, no rain, no electric displays 
 and yet the very substance of a storm is passing over people's heads- 
 We would place the essence of a storm in a barometric change above 
 
 * Vid Nodon, Bulletin de la Societe Belgs d'Astronomia. Feb. 1912. 
 
12 Latest Advances in Weather Forecasting 
 
 and below the semi-diurnal oscillation. And it may be affirmed without 
 fear of contradiction that there is no place on earth exempt from the 
 stormy barometric change. Barometrically speaking, there is no differ- 
 ence or very little difference between winter and summer; but there is 
 always a seasonal difference in solar force, moisture and temperature. 
 

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