Send 25 Cents For a 3-months' trial subscription to THE MOTHER'S The Boston Medical and BOSTON, Surgical Journal. MASSACHUSETTS. NURSERY GUIDE, numbers, 15c. Ten consecutive numbers free by mail on receipt of $1.00. THE MODERN MALADY; or, Sufferers from Nerves.' An introduction to public consideration, from a non-medical point of view, of a condition of ill-health which is increasingly prevalent in all ranks of society. In the first part of this work the author dwells on the errors in our mode of treating Neurasthenia, consequent on the wide ignorance of the subject which still prevails; in the second part, attention is drawn to the principal causes of the malady. The allegory forming the Introduction to Part I. gives a brief history of nervous exhaustion and the modes of treatment which have at various times been thought suitable to this most painful and trying disease. By CYRIL BENNETT. N. D. C. HODGES, 874 Broadway, New York. A FIRST-CLASS WEEKLY MEDICAL NEWSPAPER. ESTABLISHED 1828. Terms of Subscription: In the United States, and to Canada and Mexico, $5 00 a year in ad vance. To Foreign Countries embraced in the Universal Postal Union, $1.56 a year additional. Single This JOURNAL circulates chiefly through the New England States, and is seen by the great majority of the profession in that important district. As a means of reaching physicians it is unequalled. It is under the editorial management of Dr. George B. Shattuck, assisted by a large staff of competent coadjutors. Subscriptions and advertisements received by the undersigned, to whom remittances by mail should be sent by money-order, draft or registered letter. DAMRELL & UPHAM, 283 Washington Street, Boston, Mass. SINGLE COPIES, TEN CENTS. $3.50 PER YEAR, IN ADVANCE. TO THE SCIENTIFIC PUBLIC. College Professors and others will confer a favor by corresponding with us in regard to apparatus for the equipment of Physical, Chemical, Biological, Electrical and Engineering Laboratories. We are the largest makers of general scientific apparatus in the United States, and devote attention exclusively to high grade instruments, such as meet the most exact requirements. Special bids will be submitted upon request, and interested parties should write for abridged catalogue No. 219, which will be mailed free if this "ad." is mentioned. QUEEN & CO., Incorporated. World's Fair Exhibits-Electricity and Manufactures Buildings. 165 MINERALS. 165 166 New Store. New Departments. 167 GEO. L. ENGLISH & CO., Mineralogists, Removed to 64 East 12th Street. New York NEW METHOD OF PROTECTING BUILDINGS FROM LIGHTNING. PROTECTION FROM LIGHTNING. What is the Problem? IN seeking a means of protection from lightning-discharges, we have in view two objects, the one the prevention of damage to buildings, and the other the prevention of injury to life. In order to destroy a building in whole or in part, It is necessary that work should be done; that is, as physicists express it, energy is required. Just before the lightning-discharge takes place, the energy capable of doing the damage which we seek to prevent exists in the column of air extending from the cloud to the earth in some form that makes it capable of appearing as what we call electricity. We will therefore call it electrical energy. What this electrical energy is, it is not necessary for us to consider in this place; but that it exists there can be no doubt, as it manifests itself in the destruction of buildings. The problem that we have to deal with, therefore, is the conversion of this energy into some other form, and the accomplishment of this in such a way as shall result in the least injury to property and life. Why Have the Old Rods Failed? When lightning-rods were first proposed, the science of energetics was entirely undeveloped; that is to say, in the middle of the last century scientific men had not come to recognize the fact that the different forms of energy heat, electricity, mechanical power, etc.- were convertible one into the other, and that each could produce just so much of each of the other forms, and no more. The doctrine of the conservation and correlation of energy was first clearly worked out in the early part of this century. There were, however, some facts known in regard to electricity a hundred and forty years ago; and among these were the attracting power of points for an electric spark, and the conducting power of metals. Lightning-rods were therefore introduced with the idea that the electricity existing in the lightning-discharge could be conveyed around the building which it was proposed to protect, and that the building would thus be saved. The question as to dissipation of the energy involved was entirely ignored. naturally; and from that time to this, in spite of the best endeavors of those Interested, lightning-rods constructed in accordance with Franklin's principle have not furnished satisfactory protection. The reason for this is appar nt when it is considered that the electrical energy existing in the atmosphere before the discharge, or, more exactly, in the column of dielectric from the cloud to the earth, above referred to, reaches its maximum value on the surface of the conductors that chance to be within the column of dielectric; so that the greatest display of energy will be on the surface of the very lightningrods that were meant to protect, and damage results, as so often proves to be the case. It will be understood, of course, that this display of energy on the surface of the old lightning-rods is aided by their being more or i ss insulated from the earth, but in any event the very existence of such a mass of metal as an old lightning-rod can only tend to produce a disastrous dissipation of electrical energy upon its surface,-"to draw the lightning," as it is to commonly put. Is there a Better Means of Protection? Having cleared our minds, therefore, of any idea of conducting electricity, and keeping clearly in view the fact that in providing protection against lightning we must furnish some means by which the electrical energy may be harmlessly dissipated, the question arises, "Can an improved form be given to the rod so that it shall a 'n this dissipation?" As the electrical energy involved manifests itself on the surface of conductors, the improved rod should be metallic; but, instead of making a large rod, suppose that we make it comparatively small in size, so that the total amount of metal running from the top of the house to some point a little below the foundations shall not exceed one pound. Suppose, again, that we introduce numerous insulating joints in this rod. We shall then have a rod that experience shows will be readily destroyed-will be readily dissipated -- when a discharge takes place; an i it will be evident, that, so far as the electrical energy is consumed in doing this, there will be the less to do other damage. The only point that remains to be proved as to the utility of such a rod is to show that the dissipation of such a conductor does not tend to injure other bodies in its immediate vicinity. On this poin: I can only say that I have found no case where such a conductor (for instance, a bell wire) has been dissipated, even if resting against a plastered wall, where there has been any material damage done to surrounding objects. Of course, it is readily understood that such an explosion cannot take place in a confined space without the rupture of the walls (the wire cannot be boarded over); but in every case that I have found recorded this dissipation takes place just as gunpowder burns when spread on a board. The objects against wich the conductor rests may be stained, but they are not shattered, I would therefore make clear this distinction between the action of electrical energy when dissipated on the surface of a large conductor and when dissipated on the surface of a comparatively small or easily dissipated conductor. When dissipated on the surface of a large conductor, a conductor so strong as to resist the explosive effect,-damage results to objects around. When dissipated on the surface of a small conductor, the conductor goes, but the other objects around are saved A Typical Case of the Action of a Small Conductor. Franklin, in a letter to Collinson read before the London Royal Society, Dec. 18, 1755, describing the partial destruction by lightning of a church-tower at Newbury, Mass, wrote, "Near the bell was fixed an iron hammer to strike the hours; and from the tail of the hammer a wire went down through a small gimlet-hole in the floor that the bell stood upon, and through a second floor in like manner; then horizontally under and near the plastered ceiling of that second floor, till it came near a plastered wall; then down by the side of that wall to a clock, which stood about twenty feet below the bell. The wire was not bigger than a common knitting needle. The spire was split all to pieces by the lightning, and the parts flung in all directions over the square in which the church stood, so that nothing remained above the bell. The lightning passed between the hammer and the clock in the above-mentioned wire, without hurting either of the floors, or baving any effect upon them (except making the gimlet-holes, through which the wire passed, a little bigger), and without hurting the plastered wall, or any part of the building, so far as the aforesaid wire and the pendulum-wire of the clock extended; which latter wire was about the thickness of a goose-qull. From the end of the pendulum, down quite to the ground, the building was exceedingly rent and damsgei.... No part of the aforementioned long, small wire, between the clock aud the hammer, couid he found, except about two inches that hung to the tall of the hammer, and about as much that was fastened to the clock; the rest being exploded, and its particles dissipated in smoke and air, as gunpowder is by common fire, and had only left a black smutty track on the plastering, three or four inches broad, darkest in the middle, and fainter towards the edges, all along the ceiling, under which it passed, and down the wail. ' One hundred feet of the Hodges Patent Lightning Dispeller (made under patents of N. D. C. Hodges, Editor of Science) will be mailed, postpaid, to any address, on receipt of five dollars ($5). Correspondence solicited. Agents wanted. AMERICAN LIGHTNING PROTECTION CO.. 874 Broadway. New York Citv. Probably you take THE Electrical Engineer. HANDY BOOKS. PRACTICAL ELECTRICS, a universal handy book on every day Electrical matters, fourth edition. 135 pages, 12vo, cloth, price 75 cents. ELECTRICAL TABLES AND MEMORANDA for Engineers, by Silvanus P. Thompson, 128 pages, Illustrated, 64 mo, roan, 50 cents. A SYSTEM OF EASY LETTERING by Howard Cromwell, 32 different styles, 50 cents. THE ORNAMENTAL Penman's pocketbook of alphabets, 37 different styles, 20 cents. Books mailed post paid to any address on reSPON & CHAMBERLAIN, 12 Cortlandt St., N. Y. Most people interested in Electricity ceipt of published price. do. If you do not, now is a good time to begin. It is published every Wednesday. Subscription, $3.00 per year. Mention this paper. Pennsylvania Bedford Springs Mineral Water For Liver, Kidney and B dder Troubles. For Dyspepsia, Rheumatism and Gout. It has been used medicinally and prescribed by physicians for nearly one hundred years. DIRECTIONS:-Take one or two glasses about a Case One Dozen Half-Gallon Bottles, $4.50. Case Fifty Quarts (Aerated), $7.50. Bedford Mineral Springs Co., Bedford, Pa. Philadelphia Office, 1004 Walnut St. Newspaper Clippings. 25,000 in Stock. What do you want? Let us know. We can supply you. The Clemens News Agency, Box 2329. San Francisco, Cal. A Powerful A process that kills the taste of cod-liver oil has done good service-but the process that both kills the taste and effects partial digestion has done much more. Scott's Emulsion stands alone in the field of fat-foods. It is easy of assimilation because partly digested before taken. Scott's Emulsion checks Consumption and all other wasting diseases. Prepared by Scott & Bowne, Chemists, New York. Sold by druggists everywhere. NEW YORK, SEPTEMBER 22, 1893. THE AUGUST STORMS.* BY WALTER C. KERR, NEW BRIGHTON, STATEN ISLAND. THE havoc wrought upon vegetation in the vicinity of New York city by the recent storms perhaps deserves notice, especially considering the opportunity afforded to compare the effects of two destructive gales, only four days apart. These storms though quite similar in general character differed widely in one feature, whose destructive power might escape general notice or at least be much underrated. This feature is the amount of water in the air, which largely augments the weight of the moving column and at high velocities transforms the usually harmless wind into a formidable battering ram. Some time since Mr. William T. Davis, of New Brighton, Staten Island, mentioned that the comparative scarcity of large trees in that vicinity was probably due to high gales, and when the results of recent storms are viewed, there can be little doubt regarding this cause. The gale of August 24 is generally credited with having uprooted or broken more trees in this locality than any on record. This destruction of vegetation was widespread. In the cities and towns the streets were blocked with fallen trees and branches while the country roads were in many places impassable. Numerous white oak and chestnut trees were uprooted that to all appearances should have offered great resistance. This storm had a comparatively low wind-velocity, and a great rainfall. The gale of August 29th caused some damage to vegetation, though not nearly so much as that of the 24th. At sea it was one of the worst storms experienced in this latitude for years. It was characterized by a very high wind with little rain. It may be said that the first storm destroyed the weak trees, leaving little for the second and greater one to wreck. On the other hand it may be presumed that the first storm would cause much weakening and facilitate the efforts of the greater wind that followed. The first storm had a maximum velocity of forty-eight miles, reached by our winds about once each month without sensible damage, while the maximum velocity of the second, sixty miles, is attained less frequently than once a year and only rarely is this high rate destructive to vegetation. The following official records from the United States Weather Bureau, N. Y., furnish accurate comparisons : August 21, rainfall 3.81 inches from 7.52 P. M. August 23d to 8.15 A. M. August 24. Time, Wind velocity, Maximum velocity for one hour, thirty-seven miles at 2 A. M. 12 1 2 3 4 5 6 7 8 29 33 27 28 29 30 23 20 *Paper read at a recent meeting of the Natural Science Association of Staten Island. Maximum rate for one mile, forty-eight miles between 1 and 2 A. M. Between 2 and 3 P. M. August 24, the wind averaged thirty-five miles, with a maximum rate for one hour of fortytwo miles. At this time no rain fell and no damage resulted. August 29, rainfall .28 inches from 4 A. M. to 8 A. M. Time, 12 1 2 3 4 5 6 7 8 Wind velocity, 24 31 33 38 38 44 40 32 Maximum velocity for five minutes, fifty-four miles at 5 A. M. Maximum rate for one mile, sixty miles at 5 A. M. At this station of the United States Weather Bureau a wind velocity of forty to fifty miles is attained once a month, a wind velocity of sixty miles is attained scarcely once a year, a wind velocity of seventy-two miles is the highest on record. These figures show conclusively that, as ordinarily measured, the second storm was by far the greater; in fact, as the wind pressure is proportional to the square of the velocity, it may be seen that the effect due to wind pressure alone on August 29, should have been nearly double that of August 24. When we, however, give value to the relative rainfalls, 3.81 inches as against .28 inches, the destructiveness of the wet gale of August 24 becomes apparent. In a storm a tree must resist a column of air moving at a high velocity and to a large degree consume its energy. This energy is proportional to the mass and the square of the velocity. Dry air has small mass per cubic foot, yet at forty miles per hour yields a pressure of eight pounds per square foot; at fifty miles twelve pounds; at sixty miles eighteen pounds; at eighty miles thirty-two pounds; and at 100 miles fifty pounds. If we add to each cubic foot of air one-tenth of one per cent, by volume, of moisture, as, for instance, by partly filling it with rain drops, its weight will be nearly doubled (.0753 plus .0625), and in consequence the energy of the moving mass will be likewise doubled. One-half of one per cent of water added to the air increases the energy five-fold, and thus the wind at its maximum velocity of forty-eight miles on August 24, if burdened with this amount of moisture, would have an effect greater than a dry hurricane of 100 miles. When rain falls in calm but little water is contained per cubic foot of air, but with high winds the rainfall of a large area may be carried along nearly horizontally and massed where intercepted by vertical obstacles. It is therefore reasonable to presume that trees in exposed situations receive vastly more water per square foot of surface than is measured by rain gauges in the usual way. When wet the resistance of foliage to passing wind and rain is doubtless increased, especially when there is a tendency for the leaves and branches to mat together on the windward side, while the weight of water carried by the tree may be a considerable additional burden. It thus becomes easy to appreciate the enormous part which water plays in the destructive force of high winds on exposed trees, as well as on the more commonly noticed windfallen grain and corn. PETROGRAPHS AT LAKE PEND D'OREILLE, IDAHO. BY JOHN B. LEIBERG, HOPE, IDAHO. ABORIGINAL rock carvings or inscriptions are quite rare throughout northern Idaho. The dense forests and generally inaccessible character of the country together with a constant scarcity of natural food products furnished unsuitable conditions to sustain any considerable number of inhabitants, and those that made the country their abode appear to have been either too indolent to endure the labor required to leave any records on the rocks, or their lives did not furnish any events worth noting, in their judgment. The records we find consist mainly of carvings on trees, or of rocks of small dimensions, raised to perpendicular positions, on the summits of high bare peaks or, in rare instances, in similar situations, of small flat stones arranged in certain geometrical designs, as circles, triangles or circles within circles, or circles and triangles variously intermixed. The carvings on trees all belong to recent years, as very many of them are simply Latin crosses, showing the influence of the missionaries. These crosses schists are rather thinly bedded, have a dip of about 85°, and the wear of the lake in former ages, when its waters stood at a much higher level, has broken the strata apart and left numerous large slabs standing in an upright position. On the face of one of these tablets of rock occur the carvings as delineated in the accompanying illustration. They occupy a space eighteen feet in length, and from two feet to seven feet in height. There are twenty-eight figures evidently representing the footprints of the bear, three of the tracks with double sets of toes, three with but four toes, and one with but three toes. Three figures which may represent tracks of the cougar. One arrow head. Three points within circles. One mountain goat. Two sets of circles composed of five and six respectively, and three large figures of unknown meaning. Besides these figures there are evidences of many light scratches, but the lines are too dim are quite common around favorite hunting or camping spots in the mountains, and appear to be made with the object in view of warding off malign influences from the camping grounds. These crosses are not to be confounded with the sign plus, so commonly made by hunters and trappers throughout the deep forests, and which merely serve to attract attention to trails, locations of traps, etc. The raised stones, so common on high peaks, merely denote the passing of some individual, and may be quite recent or date back a long time. Sometimes white men raise these rocks. The symmetrical arrangements of rocks appear to be quite ancient. The stones composing them lie quite flat and are completely covered with slowgrowing saxicoline lichens on all exposed portions. The import of these figures is unknown. There is but one locality known to me in northern Idaho with true rock-carvings. It is located opposite the outlet of the Clark's Fork of the Columbia into Lake Pend d'Oreille, about one-quarter mile north from the shore. A rocky point of land rises abruptly to a height of 250300 feet above the extensive marshes bordering the river at this point. The rock is a highly silicious magnesian schist, extremely hard and difficult to chisel with even the most carefully tempered modern steel tools. The to be traced with certainty. to be traced with certainty. Nearly all the figures are thickly overgrown with close-clinging rock-lichens, rendering the whole quite inconspicuous. Close and diligent search has failed to bring any further inscriptions to light in the neighborhood. One of the most interesting features in connection with this petrograph lies in the manner of its execution. The lines of the figures are not mere scratches, but are deep, wide grooves cut smoothly into this excessively hard rock, many of the grooves forming the representations of the bear tracks. Figs. 2 are 3.2 cm. in width and 1.2 cm. in depth, while the cutting forming fig. 3 is, in its broadest portion, 5.5 cm. wide and 2.5 cm. deep. The appearance of the grooves, the smoothness of the sides and freedom from signs of chipping give cause for the belief that they were cut into the rock by friction and not by chiseling. A piece of wood properly shaped and constantly charged with water and sharp sand could be used to cut such grooves, while the same manner of tool rotated by a bow would cut round holes such as make up fig. 10. Will some of the readers of Science acquainted with the methods of the aborigines in making their rock inscriptions, inform us if such tools were in use elsewhere for doing this kind of work and the meaning of this petrograph? |