Blasius.] [Feb. 18, The Committee on Dr. Valentini's memoir was continued, The death of Mr. Charles des Moulins, at Bordeaux, on the 23d December, 1875, was announced by letter. Mr. Blasius read a defense of his theory of storms. A Brief Discussion of Some Opinions in Meteorology. BY W. BLASIUS. Read before the American Philosophical Society, February 18th, 1876. The definite establishment of the laws which regulate the weather is of so much general importance that I am induced to ask your attention to the following remarks, since the discussion of opinions cannot fail to elaborate the truth at last. In the January number of the Atlantic Monthly, there appeared a fairtempered review of my recent work on Storms," which seems to be from the pen of a practical meteorologist, between whom and myself, therefore, I am the more anxious that there should be no misunderstandings. The reviewer does not deny nor admit the truth of the theories I have advanced, but leaves them to the verdict of time. He in some important particulars, however, fails to understand the views I hold. Permit me to quote: "The West Cambridge Tornado, which first decided the direction of our author's meteorlogical studies, seems to have had a too powerful influence upon his judgment of the cyclonists,' the upholders of Redfield's Theory. Where a cyclonist sees a large storm 500 miles in diameter, on the borders of which the winds are blowing in every direction, Dr. Blasius sees many small storms, each modeled in a greater or less degree like the West Cambridge Tornado. A very striking proof that a storm may be constituted as the cyclones are supposed to be is afforded by the singular case of the ship Charles Heddle, which was caught in the borders of one of these cyclones, and sailed five times completely around its border, meeting winds blowing exactly in the directions demanded by the cyclone theory. The experience of Dr. Blasius has been limited to local storms, and he has apparently never been able to realize the existence of a storm of any magnitude. This is particularly evident in the discussion of Prof. Abbe's report on the Nova Scotia storm of August 23, 1873. Prof. Abbe is speaking of a storm at least 500 miles in diameter, but Dr. Blasius discusses it as if it were an assemblage of tornadoes each 1,200 feet wide." Now the statement that where "a cyclonist sees large storms," I see 'many small storms" is curious enough, since a considerable part of my 1876.] [Blasius. book is devoted to an attempt to prove that in many cases where the U. S. Signal Service and other cyclonists see many small storms," each independent of the other, there is in reality one large storm hundreds of miles in width. And as for the fact that "a storm may be constituted as the cyclones are supposed to be," the position I have taken is not that there are no cyclones, but that there are none in our latitude, and that the theory which would make all storms cyclones is radically erroneous. The citation of the Charles Heddle case, to which I have also alluded in my book, is not a very fortunate one, however, since it is far from being authentic. Even Dove himself, the great apostle of the cyclonic theory, calls it a sea romance," "oder auf gut muselmannisch gesprochen, etwas was gesehehen sein kænne, wenn es dem Propheten so gefallen hætte." Even if it were authentic, however, it would not conflict with any position I have taken, since the storm to which it relates was a typhoon of the Indian Ocean. The complaint that my experience has been limited to local storms, shows some confusion of ideas, since it is not to be supposed that extensive storms have avoided me, or that the researches of others are not open to me. The reviewer in another place says: "If Dr. Blasius's book were not dated from the Atlantic coast, the meteorologist could yet determine quite accurately his latitude and longitude from the types of storins he gives." This is quite satisfactory, since the professed aim of my book is to give general principles, capable of universal application, and then to show how these principles are applied to our latitude as example of the modifying effect of differing local circumstances. Meteorology is largely a science of locality, after all, as well as of the air; mountains, lakes, forests, the sea— all have their effect in determining how the general weather changes will affect us. And this is the reason why predictions for a large section of country, such as the signal service give can never be so accurate as to be of much use. That I have endeavored to show how general principles could be locally applied, probably affords the Atlantic Monthly reviewer ground for supposing my views restricted; but he cannot have read the book very carefully. So far from not being able to realize the existence of a storm of any magnitude," it is one of the main points of difference between the cyclonists and myself that, whereas they consider the area of low barometer the storm, my views make this but a part of the storm, which covers also much larger areas of high barometer in front and rear. The particular case cited, that of the Nova Scotia storm of August 23, 1873, is not at all to the point, since, instead of taking a more limited view of the phenomenon than Professor Abbe does, I hold that the storm was twice as large as Prof. Abbe supposes it to have been, and that one-half of it the Signal Service never knew at all. More than this, the half they did not see was that which was on land within their jurisdiction, and was the real Blasius.] [Feb. 18, cause of most of the tremendous destruction that occurred. The Signal Service maps of this storm merely note an "area of high barometer" coming from Manitoba on the 22d, to which they attach no significance, and which they do not connect with the Nova Scotia storm; but I feel convinced that this very same "area of high barometer" really an advance of heavy air from the North, was responsible for the loss of most of the thousand and odd vessels that were destroyed on the coast. If the Signal Service had only known its true character, they would have been able to give, at least a day ahead, forewarnings of this most terrible storm which, as it was, took them entirely unawares. In these "areas of high barometer" the cyclonists see an inexplicable something which they call an "anti-cyclone;" in which they think the air rotates in the opposite direction from that in a cyclone, and that it brings dry and fair weather. The celebrated Le Verrier, acting on this theory, on account of the advance of such an "area of high barometer" over England, predicted fair weather just before those violent storms and terrible floods which last Summer desolated so large a tract of country in France. The theory which I hold would have shown him in this "area of high barometer" an advance of the polar current, almost certain in the Summer season to produce violent rains. It was much the same case with the Nova Scotia storm. As for the statement that I have discussed this storm as if it were “an assemblage of tornadoes," (sic) I do not see any evidence of a tornado at all. A tornado is only a local incident—although a terrible one—in the passage of a Southeast storm, caused principally by the configuration of the ground, notwithstanding that the Signal Service describes one as "at least thirty miles," and "probably 240 miles" in diameter. The Atlantic reviewer states that, "as a matter of fact, the Signal Service notes all storms within the limits of the Atlantic coast and the Rocky Mountains," and "its object is to obtain the laws of them as they exist." In my book I have pointed out several instances where the advance of the polar current, producing a Southeast storm of considerable magnitude is treated by the Signal Service as a series of detached local storms, such as tornadoes, hail-storms, cloud-bursts, etc., of which they know nothing until they are over; cases of this kind are abundant in the Signal Service reports. If the object of the Signal Service is to establish laws, why-I ask it in no hostile spirit-has it as yet given no laws to science? Or why does it, as the New York Nation lately says, Keep as widely as possible aloof from the science of the country?" I have also protested against the practice of observing only at fixed hours of the day, contending that if an individual storm is to be known, it must be observed continuously so long as it lasts. The Atlantic reviewer thinks it is not necessary for the Signal Service to do this, because "these (continuous observations) are easily accessible in the quarterly reports of the meteorological office of England!" Upon this method, if you wish to know what are the distinctive characteristics of an African elephant, all you have 1876.] [Blasius. to do is to get some one's description of an Asiatic elephant, and draw your own conclusions. Mr. F. Gaster, of the London Meteorological Office says upon this point, that at Valentia, where observations are not made between the hours of 8 A. M. and 2 P. M. "Storms have been overlooked, which would doubtless have been noticed at the Central Office, where the weather is observed continuously." Is it not at the least very probable that the Signal Service, making but tri-daily observations, has overlooked storms in the same way? In my book I urge that observations of the clouds in connection with ærial currents is of the greatest importance, which the Atlantic Monthly writer attempts to meet by saying that the Signal Service has made tri-daily maps of the clouds for four years. This may be true, but it has never made observations of the intimate connection of the clouds with ærial currents, nor understood this significances. Early in 1874 I explained my views to Prof Henry of the Smithsonian Institute, in a personal interview, and he then said, "This is all new to me." He took copious notes. The Signal Service report for 1873, published after this, contains a few old plates of the cloudforms given by Howard, Pœy, and others, but with no reference to them in the text. That of 1874 contains cloud maps for one day, with no reference in the text, and contains no attempt to give the particular forms any distinctive character. The eminent meteorologist, Prof. H. Mohn, Director of the Royal Meteorological Institute at Christiania, Norway, in a letter to me says: "That you introduce the cloud forms into practical meteorology is certainly very good." It is of little use to make maps of the clouds unless we understand something of their significance. The reviewer states that I claim for myself in conjunction with exPresident Hill, of Harvard, "the credit of originating the present Signal Service storm-warnings," but that we "were anticipated by Redfield, Henry, and others." A claim of this kind is hardly worth advancing or discussing, but I wish to correct misunderstandings. All I do claim is that in 1851, before any one else, I believe, I advocated and labored for a corps of meteorological observers connected by telegraph with a central office, so that the central observer might see the whole storm continuously in all its extent from beginning to end. I would earnestly urge a popular interest in meteorology, since no other science is so open to those occupied in other pursuits, and scarcely another of so much practical importance. We all know men of no scientific acquirements, yet who are so well versed in signs of the weather that their predictions are more to be relied on for a particular locality than the very general "Probabilities" of the Signal Service. Such weather-wisdom is founded upon accurate observations of nature, and the explanation of weather signs is often very simple. For instance, it is an old Indian observation that Summer storms follow the course of rivers. The explanation of which is that Summer storms are mostly produced by the advance of colder air, which being heavier, sinks into and follows the valleys, at the bottom of which there is usually a water-course. Again, a halo round PROC. AMER. PHILOS. Soc. XVI. 97. z |