# Popular Science Monthly/Volume 18/December 1880/Correspondence

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"WHAT THE EYE SEES IN READING."
Messrs. Editors.
IN your admirable cautionary note on "The Eyesight of Readers," in the September number of your magazine, you say, "A book of five hundred pages, forty lines to the page and fifty letters to the line, contains a million of letters, all of which the eye has to take in, identify, and combine each with its neighbor."
I believe you are wrong. I don't believe we deal with letters in reading at all, except when we meet unfamiliar words. I think persons, who read rapidly recognize words and phrases without analyzing them into their elements. I think that every word has a countenance, a physiognomy, which we soon learn, and which we afterward recognize as we do the faces of our friends.
Repeatedly I have amused myself by approaching an unfamiliar sign, or handbill, or printed page. What comes first into view? Not letters, but words; and they stand identified when no single letter can be distinguished.
It lies within easy observation that the lateral oscillation of the eyes of a rapid reader is very limited. Why? He cares so little about spelling the words he reads, that he does not even present to all of them the more sensitive spots on his retinæ, but is content to leave the images of most words upon more peripheral parts where they could not be spelled.
I would not presume to inform you of the brilliant success of the experiment of teaching children to read without spelling—an experiment which I believe has been most thoroughly tried in St. Louis. In the case of children so taught, words only are scanned, the young readers being wholly ignorant of the value of letters.
I have a correspondent whose written characters could not possibly be recognized, and yet to me his letters are fairly legible. Why? Because, however far he departs from the standard of the copy-book, he always writes any given word in the same way; and, although I could not spell isolated words from his written page, I have learned to recognize them as quickly as if they were fairly printed.
I think it might be successfully maintained that there actually is not time for each letter to be separately regarded, either by the eye or the mind, in rapid reading. I read the first three pages of the "Sketch of Joseph Leidy" in three minutes, and Abercrombie could have read it much quick, er. In each minute I read four hundred words, containing more than two thousand letters. I submit that, while it is possible to see six or seven words per second, it is quite impossible to see thirty or forty letters per second.
* Dan Millikin.
* Hamilton, Ohio, September 10, 1880.
A CASE OF PROTECTIVE MIMICRY.
Messrs. Editors.
I venture to send you an account of a sparrow's performance which I witnessed some time ago, and which you may consider worth publishing. It seems to me that the publication of such observations, when known to come from a trustworthy source and bearing the stamp of probable correct interpretation, is sure to add a light and pleasant page to our journals of popular science, as well as furnish a store from which illustrations may be drawn by those needing them. You have no reason to know me or my trustworthiness, but, that I do not depend upon imaginary data for such narratives as I send, I think I may refer you to my friend and teacher. Professor W. K. Brooks, of the Johns Hopkins University, or to Professor Martin, of the same institution, although I do so this time without their know ledge or permission.
Some time since, while riding slowly along a dusty macadamized road, I was startled by the hurried flight close by my side of a small bird which dropped in the road a few paces ahead, and after a flutter in the dust sat perfectly motionless. I drew up my horse to watch events, when a moment later a hawk swooped by, but missed its prey, and went off into an adjoining field. The sparrow remained still in its place, and, all covered with dust, looked for all the world like one of the many loose stones in the road—so much so, that no wonder it should have escaped the sharp sight even of the hawk.
But one explanation of such a freak seemed possible; and when we reflect that these birds generally take to the bushes or to the lichen-spotted rail fences, when pursued by hawks, and that dust is not a constant factor of the environment, we stop to admire so bright a spark of intelligence kindled under such trying circumstances. Respectfully,
* Bolling W. Barton, M. D.
* Baltimore, September 30, 1880.
A SHOWER OF DUST.
Messrs. Editors.
In your July issue, I find a communication from Mr. Kirkwood, of Bloomington, Indiana, in regard to a deposit of dust that was observed there on the 28th March, 1880, and in which the theory is advanced, to account for its origin, that, since a similar phenomenon occurred in Europe almost simultaneously, both may be of common origin.
The following is collated from the "Weather Review" (the official organ of the United States Signal Service) for March, 1880, and it undoubtedly leads us to infer that the Bloomington phenomenon and those treated in the "Review" were identical:
No. XV.—This area appeared in British Columbia, the afternoon of the 24th; Portland barometer 0·46, and Fort Benton barometer 0·45 below the normal. Moving southeastward, it was in Idaho the morning of the 25th, and by an easterly path was central in Nebraska the afternoon of the 26th, Omaha barometer 0·75 below the normal; at that time the pressure in the entire Missouri and upper Mississippi Valleys ranged from 0·40 to 0·75 below the normal. At midnight the area was central in Iowa, at which time the pressure over the greater part of the lower Missouri and upper Mississippi Valleys was 0·60 below the normal. At that time brisk easterly winds prevailed in the entire lake-region and Mississippi Valley generally, accompanied by rain, and brisk northerly winds from the Missouri Valley westward. On the morning of the 27th the area was central in eastern Iowa—Davenport barometer 1·04 below the normal—in the afternoon in northern Illinois, and at midnight in northwestern Ohio. During the day violent wind-storms (see data regarding local storms) occurred in the upper Mississippi and lower Missouri Valleys, and in the upper lake-region, westward from the Mississippi Valley to the Rocky Mountain slope, but little or no rain falling; remarkable dust-storms prevailed. Las Cruces, New Mexico, 26th, very violent sand-storm, filling the air with dust. Leavenworth, Kansas, 27th, blinding dust-storm, almost obscuring the sun at 10 a. m. Fort Davis, Texas, violent sand-storm. Ringgold, Ohio, 27th, heavy wind and hail storm. Professor Nipher, of St. Louis, Missouri, reports this storm "as the most remarkable phenomenon of the month. It covered the entire State, except the extreme southern part. The atmosphere was filled, during the whole day, with a fine grayish dust, which, in the western part of the State and in eastern Kansas, was so dense as to obscure the light of the sun, and to render objects invisible at a distance of from one to three hundred yards. The wind was very high, coming in most cases from the west and northwest."
* P. F. Lyons.
* Leavenworth, Kansas, July 28, 1880.
MR. HERBERT SPENCER'S FACTS.
Messrs. Editors.
Allow me to say, respectfully, that Mr. Spencer impairs the public confidence in his conclusions by inattention to the reliability of what he states as facts. It is not enough that an author can cite book and page of some other writer in exact confirmation of his words. Responsibility for the truthfulness of the statement, which is the main thing, must rest upon him who repeats as well as on him who first puts it forth. A teacher of philosophy, especially, is bound to acquire a critical knowledge of the facts he uses, and to employ this knowledge judiciously for the benefit of those he attempts to instruct. In Mr. Spencer's preliminary article upon "Political Institutions," in the October number of "The Popular Science Monthly," the following statement occurs at page 6: "Having great cities of one hundred and eighty thousand houses, the Mexicans had also cannibal gods; . . . and, with skill to build stately temples big enough for ten thousand men to dance in their courts, there went the immolation of twenty-five hundred persons annually, in Mexico and adjacent towns alone, and of a far greater number throughout the country at large."
A few words concerning the one hundred and eighty thousand houses in the pueblo, not the city of Mexico. There is some difference in the estimates of the population of Mexico found in the Spanish histories, but several of them concurred in the number of houses, which, strange to say, is placed at sixty thousand. Zuazo, who visited Mexico in 1726, wrote "sixty thousand inhabitants," not houses (Prescott, "Conquest of Mexico," vol. ii, p. 112, note); the anonymous conqueror, who accompanied Cortes, says "sixty thousand inhabitants" "soixtante mille habitans" (A. Tarnaux-Campans, vol. x, p. 92); but Gomara and Martyr wrote "sixty thousand houses," and this estimate has been adopted by Clavigero ("History of Mexico," Cullen's translation, vol. ii, p. 360); by Herrera ("History of America," London edition, 1725, Stevens's translation, vol. ii, p. 360), and by Prescott ("Conquest of Mexico, vol. ii, p. 112). Solis says "sixty thousand families," instead of houses or inhabitants ("History of the Conquest of Mexico," London edition, 1738, Townsend's translation, vol. i, p. 393). This guess would give a population of three hundred thousand, although London at that same time, after centuries of growth, contained but one hundred and forty-five ​thousand inhabitants (Black's "London," p. 5). Finally, Torquemada, cited by Clavigero (ib., vol. ii, p. 360, note), boldly writes "one hundred and twenty thousand houses"; and now Mr. Spencer not only calls this Indian pueblo a "great city," but informs us that it contained "one hundred and eighty thousand houses." Torquemada had doubled the first estimates, and Mr. Spencer not only accepts the doubling, but adds upon some special authority an extra "sixty thousand houses," thus showing a tendency of mind to adopt the most extravagant views, where degrees exist. At five inmates to each house, it would give nine hundred thousand inhabitants. No doubt Mr. Spencer can furnish an authority of some kind for his "one hundred and eighty thousand houses," but that would not mend the matter, as the statement is simply so preposterous that Mr. Spencer is without excuse.
Nor is this the end of the difficulty. There can scarcely be a doubt that the houses in this pueblo, like those of the Indian tribes in New Mexico, and in Yucatan and Central America of the same period, were generally large joint-tenement houses, large enough to accommodate from ten to fifty and a hundred families in each. This, if true, raises the absurdity to the maximum point. Zuazo and the anonymous conqueror, who stated the population of Mexico at "sixty thousand persons," came the nearest to a respectable estimate, as they did not more than double the probable numbers.
I will say nothing of the annual number of human sacrifices stated at "twenty-five hundred in Mexico and adjacent towns," and, "far more than twenty-five hundred in other parts of the country," nor of the ten thousand dancers, who could dance in the courts of the great teocalli. By this carelessness concerning his statements, to put it in the mildest form, Mr. Spencer will inevitably draw and write upon some of his later works the old charge, fulsius in uno fafalsus in omnibus.M.
A MINIATURE CYCLONE.
Messrs. Editors.
The cyclone which visited a section of Montgomery County on the afternoon of the 3d of September, 1879, although insignificant in its extent and destructive power, when compared with some of those which occasionally ravage other regions of the country, possessed certain features that render it worthy of study. Its dimension and effects were such as to bring it within the compass of close examination, enabling the observer to view the phenomenon as a whole. It was a perfect little cyclone in itself, with the conflicting currents, the roaring noise, the numerous distinct whirls and the double cones in the air, with the uprooted trees on earth, all presenting a combination of features whose investigation may lend important assistance to the student of these universally interesting catastrophes.
A paper on this subject was read at one of our meetings, presenting such facts as had come at that time under the observation of the writer. Having made further explorations in conjunction with a friend who is also much interested in the phenomenon, we are prepared by a visit of inspection over the whole course of the storm, from its origin to the place of final disappearance, to make a statement of the principal facts just as they were seen.
The tree, which appears to have been the first object struck by the tempest, stands in the edge of a field prepared for sowing wheat, and covered with piles of manure. This tree was not uprooted, but the limbs were much blown about, some of them twisted round the main stem, and the singular appearance was presented of strands of manure blown into slight crevices of the trunk—sucked in, as it were, up to the height of fifteen or twenty feet; the heaps of manure were of course widely scattered.
Coming out of the field referred to, the storm fell in its fury on a family graveyard. Two large tombstones, ten feet apart, secured by iron pins let into an horizontal stone slab, were thrown flat in opposite directions, the one to the east and the other to the west of the path of the storm. The tombstones were three feet high, two feet wide, and six inches thick, weighing over three hundred pounds each. The general width of the current at this place appeared to have been about forty yards; but a tree one hundred yards cast of the graveyard was much broken. Passing next through a corn-field, where the stalks in the middle lay in the direction of the path, and those at the edge leaned generally toward the center, on into a potato-patch, where some of the vines were blown out of the ground, bringing the tubers with them, the tufted weeds sharing the same fate, the winds, truly winged, vaulted over the fence without disturbing a rail, or the trees of a wood in their course for a space of some sixty yards. Then the whirling current descended, prostrating some trees as it entered a field, where it leveled the grass as if a roller had passed along, and made three distinct shallow holes in the ground, at least a foot in length. A few stones lying near, out of their previous place, appear to have been used by the wind as an agent in digging these holes.
After leaving this field, there was an interval of perhaps half a mile in which were but slight traces of the storm. It then swooped down upon a forest thick with large trees, a number of which were uprooted, lying in different directions, and others with their upper limbs and tops much twisted ​and broken. Leaving this, the cyclone fell into a meadow, then rose, and, after a course of a few hundred yards, it descended upon an elevated section of forest. Here, about the middle of its course, the destruction was most apparent, in the way of uprooted and broken timber; and so unconformable was the lay of the prostrate trees, as to defy all the ordinary theories of cyclones.
But this spot afforded clear evidence of the successive ascent and descent of the whirling current as it swept along; for the trees where it entered the forest had only their tops and upper limbs twisted and mutilated, a series of whole trees uprooted following in the path, while again the destruction was confined to the top at the place where the storm left the woods.
The next remarkable object was a corn-field, in which the damage was conspicuous. The stalks were stripped and some blown out of the ground. The earth looked as if scraped by some hard substance. A tenant-house was nest on or near the route, but the damage was slight; a shutter was blown away, only pieces of which could be found. A bed in this house was blown against the window. Farther on, a stable was partly unroofed, and a corn-house lifted up from the piers that supported it, transported a few feet, and so gently deposited that a full hogshead of wheat uncovered was let down without spilling more than a few grains. The alarmed owner found himself unable to open the door of his house. Thus far the force of the storm had been directed only against trees of the forest; it now struck the orchards of two adjoining farms, leaving sixteen fine apple-trees prostrate.
In one of these, the trees were strewed on the ground almost in the direction of the spokes of a wheel. For the next half mile very little damage was done, the path being marked by a few broken limbs of trees. But the storm came down once more, and uprooted a number of large trees, quite in a valley.
Its violence was now exhausted; we followed the path with some difficulty half a mile farther, and then no more traces of it were to be found.
The cyclone, after a course of about five miles, ascended and dissolved away into the upper air. No part of the phenomenon was more clearly indicated than this alternate descent and rise of the whirling column as it moved along. This was manifest not only from observation of the objects on the route, but was plainly seen by persons who watched the current from neighboring hills. Filled with dust and leaves and boughs of trees, and distinctly colored, the contiguous separate whirls formed a spectacle of terrible grandeur as seen from elevated points at a distance. There were slight occasional zig-zags in the route, but for the most part it was remarkably direct, with a course bearing about ten degrees east of north, and a width varying from thirty to seventy yards.
In regard to the velocity of the current, no precise estimate can be made. The nearest approach to it would be to say that the course of five miles appears to have been accomplished in about five minutes.
Two facts afford some indication as to the dimension of the whirls that were continually forming and changing in the progress of the cyclone. In the case of the orchard-trees, described as lying somewhat in the form of spokes of a wheel, the diameter of the whirl must have been about thirteen yards, while in the graveyard it could not have exceeded ten feet.
Some persons heard, during its progress, what they liken to explosions. Some also heard a noise resembling the roar of a rail-road train, before it began its course below.
Immense cumuli clouds were piled up over the storm-clouds, their brightness contrasting strongly with the black and threatening appearance of the latter.
William Henry Farquhar. Henry C. Hallowell. :
| Rockland Sandy Springs, Maryland, March 24, 1880. | ${\begin{matrix}{\big \}}\end{matrix}$ |