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St. Francis River. Wittsburg, Ark...
Tennessee River. Florence, La.... Chattanooga, Teon
Cumberland River. Nashville, Tenn...
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54.2 69.1 45.5 71.0
STATISTICS OF THE MISSISSIPPI RIVER.
Areas of Overflow. St. Francis Basin, Commerce, Mo., to Helena, Ark. (east side of river) 6,090
2,874 sq. miles. (west side of river)
3,216 Illinois, Kentucky, and Tennessee...
616 White and Arkansas Basins (west side of river), Helena to Arkansas City...
956 Yazoo Basin (east side of river), Mempbis, Tenn., to Vicksburg, Miss. .....
6.648 Macon, Boeuf, and Tennessee Basins (west side
of river), Arkansas City to Red River...... 4,955
2,001 La Fourche Basin (west side of river), Donaldsonville to Gulf of Mexico...
BY H. L. WHITING, WASHINGTON, D.C. PERSONS familiar with the range of tide along the seaboard can hardly realize how much the waters of our great interior rivers are affected by the rainfalls and watershed upon and from the vast surrounding valleys. The records of the Mississippi River Commission give much relevant data in regard to these phenomena. The following figures bave been selected, from the voluminous reports of the Commission, to give more briefly a knowledge of facts that do not come before the general public. As an instance of the great rise and fall of the Mississippi River at Cairo — at its confluence with the Ohio — in the spring of 1891, at its low-water stage, the surface of the river was within a few inches of the top of the levee that protects the city of Cairo from inundation, and from the deck of the steamer the writer looked down into tbe streets of the city sereral feet below the line of the water rushing by with a velocity of nearly seven miles an hour. In the fall of the same year, at the low-water stage of the river, the steamer, at the same place, was fifty-one feet below the elevation at which she floated six months before; and this was not the greatest range of the river at this point. Difference between highest and lowest water-readings.
Mississippi River. St. Louis, Mo...
37.1 feet. Cairo, Ill....
53.2 New Madrid, Mo..
41.4 Memphis, Tenn.
34.5 Helena, Ark....
48.0 Mouth of White River, Ark.
48.4 Greenville, Miss..
40.8 Vicksburg, Miss.
51.1 Natchez, Miss
49.9 Mouth of Red River, La.
48 5 Baton Rouge, La..
36.0 Plaquemine, La
29.9 College Point, La..
23.7 Carrollton (New Orleans).
15.9 Atchapalaya River, Simmsport, La..
38.3 West Melville, La..
29,790 Nearly thirty thousand square miles, or three and a half times the area of the State of Massachusetts.
Although, as stated, the high-water depth of the Mississippi River at Cairo is over fifty feet, the low-water depth, on shoals and bars, does not exceed four feet. This great highway to the ocean is, therefore, at these latter seasons, practically unavailable for navigation. Ten of the large steamers of the Anchor Line, which ply between St. Louis and New Orleans, are now laid up, while the elevators of St. Louis have accumulated some nine million bushels of wheat, waiting transhipment. This is but a partial showing of the importance of the improvement of the Mississippi River, in its low-water navigation, to the commercial interests of the country; aside from the injury to agricultural interests from the overflow of the lower basins of the river.
ON THE USE OF THE COMPOUND EYES OF INSECTS.
BY R. T. LEWIS, EALING, ENGLAND.
FEW subjects connected with the study of insects have given rise to more widely differing opinions than the rationale of their complex organs of vision, the physical structure of wbich presents to us one of the most elaborate optical combinations to be found in nature, and this, too, upon a scale so minute as to require no ordinary skill on the part of the microscopist to unravel its marvels.
Attempts to work out the problem as to what is the impression produced upon the consciousness of an insect by an arrangement so complicated have seldom resulted in satisfactory conclusions, not a few failures in this respect apparently being due to inadequately clear conceptions as to the application of the laws and phenomena of refraction to the cases in point. But whether the subject is approached from the standpoint of those who regard an organ as having elaborated itself in obedience to the necessities of
25.5 40.2 51.1
1 November, 1892.
external conditions, or from the opposite position of those who the further suggestion of a means of focussing. Professor Exaver it to have been designedly contrived to meet the special re- per's experiments also prove that by the intervention of the crys. quirements of those conditions, it is a matter for surprise that any talline cones this composite, or “summation," image is erect, and should have been found to express a belief that, for distinctness of is formed at an increased distance from the corneal surface. vision and other purposes for which eyes are required, these Those who have access to the last edition of the late Dr. W. B. specialized and elaborate contrivances are little better than optical Carpenter's book, “The Microscope and its Revelations,” will have failures. Such a notion, if capable of proof, would be a unique noticed a reference to these researches, but it may be as well to exception to that perfect adaptation of means to ends, which, note that the figure on page 908 appears to have been laterally inwherecer our knowledge is complete, we find everywhere else in verted by the engraver, my own recollection and a rougb sketch nature.
taken at the time enabling me to say that in the original photoApart from the question as to whether tbe nervous structure of graph the letter R was not reversed as shown in the wood.cut, an insect's eyes enables it to utilize rays which are beyond the and the church faced the other way. compass of our own, it is clear that the nature of light requires Assuming, therefore, that distinct and otherwise perfect vision in all organs of vision a structure wbich is analogous in its optical is enjoyed by the possessors of compound eyes, it is reasonable to principles; that is, there must be the means of forming an image, suppose that, if we desire to know what is the raison d'etre of a sensitive screen upon which to receive it, and a connecting line their complex structure, we shall be most likely to find the analong which the received vibrations may be conveyed to the ulti. swer, if we proceed upon lines indicated by the further assumpmate seat of the sensorial impressions. Hence we find a lens, a tion, that it is required to meet some special necessity arising from retina, and an optic nerve to be common to all. We may also conditions of life which differ from those of other creatures. infer that the external physical requirements will be approximately Pursuing the inquiry in this direction the following considerathe same, so that the vibrations must be of proper quality, they tions make it probable that such conditions may be recognized in must be of sufficient intensity, and they must impinge upon the connection with the extremely rapid movements of insects in retina for a sufficient time to enable its sympathetic fibres to re- flight. spond to and take up the impulses imparted.
The angular diameter of the field of distinct vision in the human The first difficulty which we meet with in approaching the sub- eye (as distinguished from the visual angle) is much smaller than ject is one which does not apply to insects alone, and therefore is commonly supposed, experiment shows that it varies with in. does not enter exclusively into present considerations.
dividuals, but, for present purposes of illustration, we will call it In the case of human vision tbe optic angle is so small that each 10°. The inconvenience which would otherwise arise from so eye sees the same object, indeed confusion is experienced and a circumscribed an area is in practice largely compensated for by double image is perceived unless the optic axes are so converged the celerity and freedom of motion common to the eyes and head, upon the object as to bring its image upon the correspondingly by virtue of which also we are able to neutralize the effect of our sympathetic portions of each retina. But in the case of some own movements, and, within certain limits, to perceive moving animals, and in that of birds, the increase of the optic angle pre- objects which would otherwise cross the field in less time than cludes the possibility of such co-ordination, so that an entirely the minimum required for the production of a distinct retinal dissimilar picture is presented to each eye, and a further compli- image. The exact duration of this period is a matter of personal cation is introduced in the case of the chameleon, whose eyes are equation, but may usually be taken as about to of a second. Now capable of independent movement in every direction within the it is a matter of common experience that when travelling in a limitations of their sockets. We are unable to realize in our own railway train at the rate of, say, fives miles an hour, we can, with minds wbat the effect of this may be, because, with the exception fixed vision, clearly distinguish the flowers growing adjacent to of impressions received through the sense of touch, we have no the track, but, as the speed increases, we become less able to do analogous experience, but we may readily conceive it to be a so, until, at 50 miles an hour, they cross the visual area too matter of interpretation by which the wide extension of the visual rapidly to leave more than an indistinct impression of horizontal field induces the perception of a panoramic view of the surround- lines. It is, however, conceivable that if, as soon as an object ings; and if to eyes which are laterally situated we add also others had traversed the field of one lens, it came successively within on the vertex, with divergent axes as we find in the ocelli of the scope of nine others, which, without break of continuity, many insects, we may further imagine that an extension of the would project its image upon the same portion of the retiva, the panorama vertically may present a picture embracing an area of persistence of the image would be increased tenfold, with the obmore than half a hemisphere.
vious result that the flowers would then be seen as clearly whilst But when we come to regard vision by means of compound passing them at 50 miles per hour as they would be under ordi. eyes, such as we find in insects, other considerations present them- nary circumstances at one-tenth the speed. selves and it is obvious that the question as to "wby and where- If there is truth in this suggestion, that the use of compound fore” requires another answer. I should like to be allowed here eyes is to enable their possessors to enjoy distinct vision during to make a protest against the continued application of the term rapid flight, it would appear to derive support from the fact that "facetted” to the corneal surface of the compound eye, as con- we find, as a rule, that in larvæ and in insects wbich are wingless veying an idea which is not strictly correct. At a recent conver- the eyes are either simple, or that the ocellites, of which they are zatione I found, amongst other objects exhibited, a plano-convex compounded, are comparatively few in number; whilst in those lepse, the curved surface of which was ground off into numerous with wings the compound character is developed to its highest actual facets, and visitors were invited to look through this from degree in genera whose powers of fligbt are most remarkable. its plane face in order to realize the effect produced by the Instances are not wanting in which the eyes of apterous females “facetted” eye of an insect. I need not point out that both are simple, wbereas they are compound in the case of the winged structurally and optically this conception was entirely erroneous. males of the same species. The structure of the compound eye is, however, now so well That such extremely rapid flyers as the dragon-flies and predaknown that I do not propose to enter upon it here at any length, tory Diptera are endowed with acute and accurate powers of but will merely refer to the recent researches of Professor Exner vision seems to require no further proof than is afforded by the and others as showing (1) that, contrary to previous speculations, unerring manner in which they strike and capture other insects it is capable of forming a distinct image of considerable ampli. which are also on the wing. tude, towards which each ocellite contributes its share; (2) that in the picture so produced very many of the pictures formed by adjacent ocellites are either superposed or overlap each other in PROFESSOR SOPHUS RUGE of Dresden, an authority on matters such a way that the corresponding portions of each become coin- relating to the discovery and exploration of America, pronounces cident upon the retina; and (3) that it is bighly probable that the Mr. Winsor's “Columbus” “the most important contribution structure of the organ provides an arrangement which serves a that North America has made to the present commemoration" of purpose equivalent to that of the iris in the vertebrate eye, with 1492.
moving at an equal rate over the dial would point to the true hour by Turkish time at all seasons of the year, day and night. In fact, the problem seems to me so easy of solution that I can only explain the non-appearance of such clocks in the market by the supposition that no actual demand exists for them.
NOTES UPON THE ACTION OF DRUGS AND AGENCIES
UPON THE RESPIRATORY MOVEMENTS.
BY HORATIO C. WOOD, M.D., LL D. (YALE), UNIVERSITY OF PENN
BY F. A. SEELY, WASHINGTON, DC. MANY years ago I ventured the opinion that the development of the mechanical clock was hindered for many centuries by the general use of the Roman system of hours. I am more than ever convinced of this. It is perfectly well known that prior to the Christian era trains of gearing and other mechanical expedients were in use whereby the band of a clock could be made to travel with uniform motion on a dial. There was, to be sure, no true mechanical escapement, but Ctesibius had devised what I venture to call a water escapement, which, under certain restricted conditions, performed the true function of that element of the modern clock. But the ingenuity of the times was not adequate to the production of the varying movement necessary to keep time in a system in which the length of the hours was constantly changing; and so the clock waited many centuries until the system of hours was changed.
This subject bas been brought quite forcibly to my mind by coming into the possession of a number of German and Swiss patepts for clocks designed to keep Turkish time.
It appears from the specifications that the Turkish system of bours is practically identical with that of ancient Rome, the day commencing and ending with suprise, and the middle being at sunset, the two periods of day and night being divided into six bours each, which constantly vary in length with the change of season.
It is obviously impracticable to make up a railroad time-table on sucb a system, or to accommodate it to numerous other requirements of modern social life; and therefore the wonder is that anybody should think it worth while to construct a clock adapted to this system; but, as the patentees are in all cases residents of Constantinople, it may be inferred that, in devising these clocks, they are endeavoring to minister to a felt want of that capital.
The device employed is of the same character in all the patents, though in some automatic, in others requiring frequent attention. It consists in so adjusting the governing member (pendulum or balance-wheel) as to give it a faster or slower rate from month to month; that is to say, in the winter months, when the period from suprise to sunset is short, to quicken the action of the movement so that the hand shall pass in proportionately less time over that portion of the dial which represents the hours of daylight than it does in summer, when the days are long. It is obvious at once that this does not accomplish the purpose sought for, and the inference is natural that in the German and Swiss Patent Offices the question of utility cannot have been raised on these applications. If the pendulum is adjusted to a slow beat in the month of June, when the hours from sunrise to sunset are long, it might measure time during the day, but tbat same slow beat will destroy its capability of measuring off the short hours of the night. A parallel statement is true for the month of December. For this reason these inventions are useless, though they may serve the purpose of the patentees by imposing on the credulous Moslem.
It does not seem impossible in the present state of the arts to construct a time-piece capable of marking off this kind of bours with reasonable precision. The exactness of an astronomical clock or even of an ordinary kitchen clock would be unnecessary. But the inventions above referred to do not approach a solution of the problem, the key to which is to be found in a clock presented to this Government by that of Japan at the close of the Centennial Exposition. In this the hand moves around the dial at a uniform rate throughout the year, the adjustment for different seasons being accomplisbed by shifting the figures on the dial. It is many years since I have seen this clock, but, as I recollect it, the top of the dial represents sunrise and the bottom sunset, the balf-circumference on each side being divided into five hours by a set of figures which can be shifted in place as the seasons change so as to make the day hours long and the night hours short, and vice versa, the sunset hour being shifted also.
I see no great difficulty in producing this shifting of the supset hour automatically to the right or left as the season may require, nor does it appear to me insurmountable to connect the intermediate bours with the supset hour so that they shall be shifted proportionately with it. With such a contrivance an hour-band
THE results of a research which I have recently completed in the laboratories of the University of Penusylvania, although bearing very directly upon practical medicine, have, I think, sufficient scientific interest to be noted in the columps of Science.
Hitherto, the study of the action of agencies and drugs upon respiration has been made chiefly, if not solely, by noticing their effects upon the rate of respiratory movements. It is evident, however, tbat increased activity of rate does not necessarily imply increased activity of function, since the respirations, though more frequently repeated, may be so shallow as to have little effect. Aided by Dr. David Cerna, now of the University of Texas, I have measured the amount of air taken in and out of the lungs of the dog under different conditions.
Emotional or nervous excitement was found to be a most potent agency; the dog seemingly expressing his feelings in bis respiration as completely as a human being expresses bis in his face; so that during excitement more than twice as much air is moved as during quiet. It has long been known that the dog, having practically no sweat-glands, cools himself through the respiration; and so it was found that heating the animal, by such arrangement of apparatus as not to cause pain, nor to bring hot air in contact with the lungs, nearly doubled the respiratory movement of air. Heat, therefore, is to the dog a powerful respiratory stimulant; when in excess, however, it depresses function, as it was found that if the heating were continued the air movement became almost null. The rapid respiration seen in human beings suffering from ferer, indicates that they are affected by heat similarly to the dog.
Chloral was found to be a more positive, persistent, and certain respiratory depressant than the morphine salts; it always reduced the air movement, and the reduction, with repeated and increasing doses of chloral, was progressive, until finally respiration was completely arrested.
The actions of atropine, cocaine, and strychnine were studied both in the normal and in the chloralized dog. Each of these alkaloids was found to be a powerful respiratory stimulant, increasing most markedly the air movement. The rather unexpected result was reached that cocaine is probably the most powerful of the three, but that strychnine is the most persistent and certain in its action. Thus, whilst cocaine seemed to be almost powerless against overwhelming doses of chloral, the influence of strychnine never failed to be manifested.
The bearing of this research upon practical medicine is very evident. During the experimental preparation for my address before the Berlin Medical Congress in 1890, I discovered the great power of strychnine over the respiratory centres when almost completely paralyzed by chloroform or ether; a discovery which led to the universal practical use of strychnine in the treatment of the accidents of anæstbesia. Atropine has long been used in narcotic poisoning, but its value as a respiratory stimulant within the last year or two has been very seriously challenged. Our research, however, re-demonstrated its power as a respiratory stimulant. Cocaine bas been used to some extent as a respiratory stimulant, but it seems to be much more efficacious than is gen. erally thought. It was found in our research that in the deeply chloralized dog, after respiration bad been brought up as far as possible by one respiratory stimulant, the second stimulant was able to still further increase the extent and power of the respiratory movements. I have apparently saved human life in respiratory failure, by adding cocaine to the strychnine which was being given in as large dose as was thought justifiable. Cocaine
“ As a
and strychnine, however, have so much similarity of action upon marginal drift holds to the bipartite or tripartite or multipartite the spinal cord that the use of one of them would probably some- character of glacial deposits and glacial history. This succession what increase any danger that may have been incurred by the is not admitted by the Reverend Professor Wright. Accordingly, administration of large doses of the other.
his ideas concerning early man have no definite time-basis and On the other hand, atropine has little influence upon the cannot be discussed intelligently by modern archæologists — it spinal cord, its general physiological action being quite distinct would be as easy to discuss the opinions of an author who confrom that of cocaine or strychnine. It is therefore probable that founded not only all the successive dynasties recorded in the by the consentaneous use of atropine and strychnine, or of atro. monuments and hieroglyphs of Egypt but also the works of the pine and cocaine, the physician may obtain the advantage of modern fellahin, or of a genealogist who argued that the families wbat, many years ago, I spoke of as the “crossed action of of a dozen successive generations dined together at the same drugs; the two drugs touching and reinforcing one another in board. As an exposition of the antiquity of man and the glacial their influence upon the respiratory functions, and spreading wide theory, • Man and the Glacial Period " is a cry from the tombs of apart from each other in their unwished for and deletereous a dead past; it represents the primitive knowledge of a quartereffects.
century ago, and might then have been considered authoritative; In conclusion, for the sake of any one who may be interested in but its publication to-day is an offense to science. the details of this research, it may be stated that it will shortly be Professor Wright objects to Dr. Brinton's "flippant treatpublished in full in the English Journal of Physiology.
ment” of the Nampa figurine, and insists that a geologist who happened to detect the fraud on the ground should burden scien
tific literature with some detailed statement. It does not seem LETTERS TO THE EDITOR.
to occur to him that the gentleman in question avoided rushing Correspondents are requested to be as brief as possible. The ioriter's name into print simply because the fraud was too transparent to deis in all cases required as proof of good faith.
ceive geologists, who alone are competent to deal with questions On request in advance, one hundred copies of the number containing his communication will be furnished free to any correspondent.
concerning the geologic antiquity of man. Respectable and cul. The editor will be glad to publish any queries consonant with the character
tured gentlemen seem indeed to have been deceived by this alof the journal.
leged - find," — but they were not geologists; so, too, respectable Man and the Glacial Period.
and cultured people, including an illustrious naturalist, have been
deluded by a Philadelphia adventurer with an alleged motor, A MISLEADING paragraph in Dr. Brinton's otherwise excellent
but no physicist was deceived; in like manner, intelligent and review of a recent publication under the above caption,' in conenection with the Reverend Professor Wright's response,' seems to
honest people have been deluded by a brazen pretender into the
belief that the heavens may be frightened into tears by cannondemand a further word. Dr. Brinton errs in saying
ading — but the meteorologists are not deluded; and the circleglacialist, the author of this volume stands among the first in the
squares and perpetual-motion inventors are abroad in the land, country, and bis long study of that remarkable period in the geo
yet the mathematicians and the mechanicians are not deceived. logic bistory of our planet invests everything he says about it with
And it would be folly for the physicist, the meteorologist, the uncommon authority."
mathematician, and the mechanician to rush into print and adverWithin recent years there has grown up a new branch of geo
tise each new fraud, for thereby the press would be flooded and logic science, which has been called by its devotees "geomorphic
libraries crowded, while fraud would only flourish the more for geology,” “ 'geomorphology," and still more acceptably “geo
the advertising. So long as poor human nature remains as it is, morphy," and which is frequently spoken of as the “ New
the knave and the dupe we shall always have with us; and it is Geology.” It is the function of geomorphy to read geologic bis
to be regretted that a presumably competent authority in his own tory from earth-forms, as the older geology read history from
specialty of theology should be willing to assume either rôle in deposits and their fossils. Beginning a score of years ago with
another line of activity. Powell's conception of the “ base-level,” at which erosion ceases,
The author of the work has indeed visited many existing glathe primary idea has extended and expanded until now the geolo
ciers, and his observations would be of value to geologists if they gist not only recognizes ancient base-levels in certain topographic
could be accepted with confidence. A case in point is his measforms, but is able to determine from steepness of slopes and other
urement of the rate of flow in Muir glacier, in which he emtopographic relations the rate at which erosion bas proceeded in
ployed primitive methods and recorded a result so extraordinary the past, and thereby the attitude and altitude of the land during earlier ages. Tbis branch of science has been successfully pur
as to challenge credulity. Subsequently, the measurement was
repeated by Professor Reid by a superior method, with a widely sued by a nuuiber of geologists in this country and a few abroad,
different result which is in harmony with all other observations. and is taught in three or four universities; and it has been found of especial use in the study of glacial deposits It is, however, a
Instead of acknowledging his evident blunder, or even passing over
the matter in silence, Professor Wright has the assurance to sealed book to Professor Wright; not a syllable in his latest work,
“ talk round” the issue (p. 47), and thereby impugns the excelor in any other of his many publications, or in his public utter
lent work of a later observer. ances before scientific societies, suggests that he is aware of the
“Man and the Glacial Period” is published by a reputable existence of the New Geology. Within two decades the discriminating genius of Chamberlin
house as one of an “International Scientific Series,” and thereby and a score of fellow-workers in this country has thrown much
acquires a respectability to which otherwise it could not aspire. light on the events and episodes of the glacial period. Largely
Dr. Brinton bas fairly, albeit charitably, shown its weakness through the application of geomorphy, it has been shown that the
from the standpoint of anthropology; other reviewers have shown
that it sinks even lower when viewed from the standpoint of glacial deposits of north-eastern America represent two, three, or more distinct ice invasions occurring at different epochs in a long impressions as to the profession and standing of the author. Thus,
geology. In other ways, too, the title-page conveys erroneous period, and that the earliest of these deposits is many times older
he takes unto himself the title “Assistant on the United States than the latest - indeed the leading authorities agree that if the
Geological Survey.” The facts are, that he was temporarily post-glacial period be represented by unity, then the entire glacial
employed by one of the collaborators of the bureau largely for the period must be represented by two figures. This succession of ice deposits and ice invasions is not, indeed, recognized by some of
purpose of testing his competence as an observer; and that the
test resulted unsatisfactorily to the bureau and was brought to those glacialists whose observations bave been confined to regions
an end several years ago. in which only a single deposit is represented; but with one or two
In brief, the world would be wiser if the book were not exceptions (including our author's namesake, A. A. Wright, pro
W. J. MOGEE. fessor of geology at Oberlin) every geologist who has studied the
Washington, D.C. · Science, vol. XX., 1892, p. 249.
3 Eg., Professor T. C. Chamberlin in The Dial, Vol. XIII., pp. 303–306, No. * Op. cit., pp. 275-277.
vember 16, 1892.
Pseudaurora Borealis ; or, What was It?
few instances I have seen humming-birds perch upon the bark THE observations which I am about to recount may not be new
below the holes in order to drink long without heing forced to to others, but, as I have failed to see or hear of any such after
keep their wings moving while enjoying the sweet sap.
In some cases I have placed small birch-bark cups upon trees several years' waiting, I communicate mine, hoping that by doing so I may call them out if there are any. The business portions of
frequented by the sap-suckers and their guests, and in each such Minneapolis, Mion., had for many years been lighted by the
instance the humming-birds have been as quick as the woodBrush system of electricity, during which time that method of
peckers to discover the diluted maple syrup with which the cups street illumination had been extended considerably in all direc
were filled, and to drink it in considerable quantities. I rememtions, leaving, however, much more that continued to be lighted
ber seeing one drink for sixty seconds, with a ten seconds' rest in
the middle of the minute. by gas and oil. I had occasion to visit the suburbs of the city under circumstances which delayed my return until a very late
Most of the “ orchards” at which I have seen humming-birds hour, and for a considerable portion of my way the latter method
as visitors from year to year have been composed of red maples of lighting prevailed. On passing into the electrically-lighted
or gray birches. At one of tbe birch orchards I shot two humsection, my attention was arrested by the appearance of the aurora
ming-birds, a male and a female, in order to ascertain whether borealis, or northern lights.
more of their kind were visiting the holes. Only nine minutes It being in the month of February, and their appearance at that
elapsed before another was at the holes drinking.
FRANK BOLLES. season by no means a rare event, while the lateness of the hour,
Cambridge, Nov. 28. and the severity of the cold, with the air so filled with frost as to give an appearance of a light fog, I was hastening forward as rapidly as I could on foot, when I noticed that the aurora had
Sense of Direction. disappeared, but after a few steps more it reappeared. Pausing a
SOME time in the fifties, in Oregon, a party of prospectors took moment, I saw there was no mistaking the fact of my seeing a
a mule team, wagon, and camping equipage on a prospecting genuine display of northern lights, I again went forward with the
tour. In order to be correct in their local geography, and to resame experience of interruption. This circumstance awakened a
trace their steps should they find anything worthy of a re-visit, suspicion that the phenomena were in some way to be accounted
they took a civil engineer along, who took the bearing of every for by the presence of the electric lights, and, after another brief
course and the distance was chained. pause to make myself assured of the certainty of my observations,
When they gave up the prospecting enterprise, their route had I went back along the way I had come until fully out of the zone
been so tortuous that they decided to take the direct route for the of the Brush lights, and well into that of the gas-lamps, where I
The engineer footed up the latitudes and departures found no signs of an aurora.
of the courses run, and made a calculation of the course home, Returning slowly towards and into the former illumination, all
and all struck for the home camp. When they reached the end of the observations were repeated precisely as at first, until baving
of their course, night bad overtaken them, and they found theinpassed a given burner, when the phenomena again ceased. After
selves, not in the home camp, but in the woods, with no objects repeatedly changing my position in relation to a special burner in
or land-marks that any of the party could recognize. a northern and southern direction, during which I discovered that
As the engineer took no "back-sights,” or check bearings, be the phenomena was most distinct when I was observing them at
said that local attraction somewbere in their journey bad thrown or about the angle of 60° to the burner, a corresponding more
him off a little and that they were in the neighborhood of the ment east and west gave no more facts, and after once more noting
At this, the driver turned one of bis mules loose, the characteristic movements of the serrated columns of partially
which went directly to the camp, about three-quarters of a mile prismatic radiations of the auroral beams along the penumbrated
distant. As the mules were not allowed to run at large, for fear arc, I went on my way resolved to keep a good outlook for another
of wandering off or being stolen by Indians, this mule had never such observation, but it has never come after nearly five years
before been orer that route, and musi have had a sense of direcof waiting. If others have noticed the same, or similar phenomena,
tion. It was a joke on the engineer which he did not relish, it will be gratifying, and in order, for them to say so.
though it had great staying qualities ” P. L. NATCH, M.D.
JOHN T. CAMPBELL. Anacortes, Washington, Nov. 3.
Rockville, Ind., Nov. 14.
The Humming-Bird's Food.
Electrical Phenomena on the Mountains of Colorado. For three years I have made a special study of the habits of the IN Science for Sept. 23, Mr. O. C. Chariton describes a mounyellow-bellied, or sap-sucking woodpecker (Sphyrapicus varius), tain experience, and inquires if it is common or dangerous. as found in the White Mountains of New Hampshire. The birds The peculiar buzzing and crackling sound, the standing of the arrive in that region near the middle or 20th of April, and remain hair on end, etc., are extremely common on the mountains of until about the middle of October. During the whole of this period Colorado. The prospectors, miners, and drivers of pack trains to they derive the more important part of their food-supply from the high mines (above 11,000 feet) live in the midst of these sap-yielding holes wbich they drill through the bark of red maples, electrical phenomena, and often find much amusement in observred oaks, poplars, white and gray birches, the white ash and some ing their effect on the average “tenderfoot,” especially when lady other trees and shrubs. In every instance where I have found a tourists, as not seldom happens, find their long hair slip from the well-marked drinking place established by the sap-suckers, hum- fastenings and stand up like the fabled head-dress of the Furies. ming-birds have been regular attendants upon it during the sum- I have repeatedly heard the sounds at elevations between 6,000 mer months.
and 7,000 feet, but they are much more noticeable at higher eleva. I have paid hundreds of visits to these “orchards” of the sap- tions, where they are sometimes terrific. They sometimes mark suckers, and have watched them for many hours at a time. By the tension of the air just preceding a discharge of ligbtning, but so doing I have ascertained that, as a rule, one individual hum- in general tbey are harmless. I have many times noticed them ming-bird seems to acquire a sort of easement in the sap-fountains proceeding with hardly any interruption wbile the lightning was of the woodpeckers, and if another ruby-throat attempts to drink leaping from cloud to cloud overhead. They are caused by the sap at his spring, violent resistance is offered.
passage of an electrified cloud, and the effect is rather worse when The humming birds, at “orchards” wbere they are not molested one is in the midst of the cloud. On these mountains the maniby the woodpeckers, drink scores of times in the course of the festation of intense electrical phenomena is seldom seen except long summer day. Wben not drinking they are usually perched when there is hail or pellet snow, or the most violent summer op twigs a few yards from tbe holes, keeping their nervous heads showers; and the latter usually have bail in some part of the wagging from side to side while watching for intruders. In a storm. The loudest buzzings I have ever beard came while a