Part 9

Ten years later a white diamond of a little less than four carats' weight came to light in a collection of pebbles found in Oregon, Wisconsin, and brought to the writer for examination. The stones had been found by a farmer's lad while playing in a clay bank near his home. The investigation of the subject which was thereupon made brought out the fact that a third diamond, and this the larges of all, had been discovered at Kohlsville, in the same State, in 1883, and was still in the possession of the family on whose property it had been found.

As these stones were found in the deposits of "drift" which were left by the ice of the Glacial period, it was clear that they had been brought to their resting places by the ice itself. The map reveals the additional fact, and one of the greatest significance, that all these diamonds were found in the so-called "kettle moraine." This moraine or ridge was the dumping ground of the ice for its burden of bowlders, gravel, and clay at the time of its later invasion, and hence indicates the boundaries of the territory over which the ice mass was then extended. In view of the fact that two of the three stones found had remained in the hands of the farming population, without coming to the knowledge of the world, for periods of eleven and seven years respectively, it seems most probable that others have been found, though not identified as diamonds, and for this reason are doubtless still to be found in many cases in association with other local "curios" on the clock shelves of country farmhouses in the vicinity of the "kettle moraine." The writer felt warranted in predicting, in 1894, that other diamonds would occasionally be brought to light in the "kettle moraine," though the great extent of this moraine left little room for hope that more than one or two would be found at any one point of it.

In the time that has since elapsed diamonds have been found at the rate of about one a year, though not, so far as I am aware, in any case as the result of search. In Wisconsin have been found the Saukville diamond, a beautiful white stone of six carats' weight, and also the Burlington stone, having a weight of a little over two carats. The former had been for more than sixteen years in the possession of the finder before he learned of its value. In Michigan has been found the Dowagiac stone, of about eleven carats' weight, and only very recently a diamond weighing six carats and of exceptionally fine "water" has come to light at Milford, near Cincinnati. This augmentation of the number of localities, and the nearness of all to the "kettle moraines," leaves little room for doubt that the diamonds were conveyed by the ice at the time of its later invasion of the country.

Having, then, arrived at a satisfactory conclusion regarding not only the agent which conveyed the stones, but also respecting the period during which they were transported, it is pertinent to inquire by what paths they were brought to their adopted homes, and whether, if these may be definitely charted, it may not be possible to follow them in a direction the reverse of that taken by the diamonds themselves until we arrive at the point from which each diamond started upon its journey. If we succeed in this we shall learn whether they have a common home, or whether they were formed in regions more or less widely separated. From the great rarity of diamonds in Nature it would seem that the hypothesis of a common home is the more probable, and this view finds confirmation in the fact that certain marks of "consanguinity" have been observed upon the stones already found.

Not only did the ice mantle register its advance in the great ridge of morainic material which we know as the "kettle moraine," but it has engraved upon the ledges of rock over which it has ridden, in a simple language of lines and grooves, the direction of its movement, after first having planed away the disintegrated portions of the rock to secure a smooth and lasting surface. As the same ledges have been overridden more than once, and at intervals widely separated, they are often found, palimpsestlike, with recent characters superimposed upon earlier, partly effaced, and nearly illegible ones. Many of the scattered leaves of this record have, however, been copied by geologists, and the autobiography of the ice is now read from maps which give the direction of its flow, and allow the motion of the ice as a whole, as well as that of each of its parts, to be satisfactorily studied. Recent studies by Canadian geologists have shown that one of the highest summits of the ice cap must have been located some distance west of Hudson Bay, and that another, the one which glaciated the lake region, was in Labrador, to the east of the same body of water. From these points the ice moved in spreading fans both northward toward the Arctic Ocean and southward toward the States, and always approached the margins at the moraines in a direction at right angles to their extent. Thus the rock material transported by the ice was spread out in a great fan, which constantly extended its boundaries as it advanced.

The evidence from the Oregon, Eagle, and Kohlsville stones, which were located on the moraine of the Green Bay glacier, is that their home, in case they had a common one, is between the northeastern corner of the State of Wisconsin and the eastern summit of the ice mantle--a narrow strip of country of great extent, but yet a first approximation of the greatest value. If we assume, further, that the Saukville, Burlington, and Dowagiac stones, which were found on the moraine of the Lake Michigan glacier, have the same derivation, their common home may confidently be placed as far to the northeast as the wilderness beyond the Great Lakes, since the Green Bay and Lake Michigan glaciers coalesced in that region. The small stones found at Plum Creek, Wisconsin, and the Cincinnati stone, if the locations of their discovery be taken into consideration, still further circumscribe the diamond's home territory, since the lobes of the ice mass which transported them made a complete junction with the Green Bay and Lake Michigan lobes or glaciers considerably farther to the northward than the point of union of the latter glaciers themselves.

If, therefore, it is assumed that all the stones which have been found have a common origin, the conclusion is inevitable that the ancestral home must be in the wilderness of Canada between the points where the several tracks marking their migrations converge upon one another, and the former summit of the ice sheet. The broader the "fan" of their distribution, the nearer to the latter must the point be located.

It is by no means improbable that when the barren territory about Hudson Bay is thoroughly explored a region for profitable diamond mining may be revealed, but in the meantime we may be sure that individual stones will occasionally be found in the new American homes into which they were imported long before the days of tariffs and ports of entry. Mother Nature, not content with lavishing upon our favored nation the boundless treasures locked up in her mountains, has robbed the territory of our Canadian cousins of the rich soils which she has unloaded upon our lake States, and of the diamonds with which she has sowed them.

The range of the present distribution of the diamonds, while perhaps not limited exclusively to the "kettle moraine," will, as the events have indicated, be in the main confined to it. This moraine, with its numerous subordinate ranges marking halting places in the final retreat of the ice, has now been located with sufficient accuracy by the geologists of the United States Geological Survey and others, approximately as entered upon the accompanying map. Within the territory of the United States the large number of observations of the rock scorings makes it clear that the ice of each lobe or glacier moved from the central portion toward the marginal moraines, which are here indicated by dotted bands. In the wilderness of Canada the observations have been rare, but the few data which have been gleaned are there represented by arrows pointed in the direction of ice movement.

There is every encouragement for persons who reside in or near the marginal moraines to search in them for the scattered jewels, which may be easily identified and which have a large commercial as well as scientific value.

The Wisconsin Geological and Natural History Survey is now interesting itself in the problem of the diamonds, and has undertaken the task of disseminating information bearing on the subject to the people who reside near the "kettle moraine." With the co-operation of a number of mineralogists who reside near this "diamond belt," it offers to make examination of the supposed gem stones which may be collected.

The success of this undertaking will depend upon securing the co-operation of the people of the morainal belt. Wherever gravel ridges have there been opened in cuts it would be advisable to look for diamonds. Children in particular, because of their keen eyes and abundant leisure, should be encouraged to search for the clear stones.

The serious defect in this plan is that it trusts to inexperienced persons to discover the buried diamonds which in the "rough" are probably unlike anything that they have ever seen. The first result of the search has been the collection of large numbers of quartz pebbles, which are everywhere present but which are entirely valueless. There are, however, some simple ways of distinguishing diamonds from quartz.

Diamonds never appear in thoroughly rounded forms like ordinary pebbles, for they are too hard to be in the least degree worn by contact with their neighbors in the gravel bed. Diamonds always show, moreover, distinct forms of crystals, and these generally bear some resemblance to one of the forms figured. They are never in the least degree like crystals of quartz, which are, however, the ones most frequently confounded with them. Most of the Wisconsin diamonds have either twelve or forty-eight faces. Crystals of most minerals are bounded by plane surfaces--that is to say, their faces are flat--the diamond, however, is inclosed by distinctly curving surfaces.

The one property of the diamond, however, which makes it easy of determination is its extraordinary hardness--greater than that of any other mineral. Put in simple language, the hardness of a substance may be described as its power to scratch other substances when drawn across them under pressure. To compare the hardness of two substances we should draw a sharp point of one across a surface of the other under a pressure of the fingers, and note whether a permanent scratch is left. The harder substances will always scratch the softer, and if both have the same hardness they may be made to mutually scratch each other. Since diamond, sapphire, and ruby are the only minerals which are harder than emery they are the only ones which, when drawn across a rough emery surface, will not receive a scratch. Any stone which will not take a scratch from emery is a gem stone and of sufficient interest to be referred to a competent mineralogist.

The dissemination of information regarding the lake diamonds through the region of the moraine should serve the twofold purpose of encouraging search for the buried stones and of discovering diamonds in the little collections of "lucky stones" and local curios which accumulate on the clock shelves of country farmhouses. When it is considered that three of the largest diamonds thus far found in the region remained for periods of seven, eight, and sixteen years respectively in the hands of the farming population, it can hardly be doubted that many other diamonds have been found and preserved as local curiosities without their real nature being discovered.

If diamonds should be discovered in the moraines of eastern Ohio, of western Pennsylvania, or of western New York, considerable light would thereby be thrown upon the problem of locating the ancestral home. More important than this, however, is the mapping of the Canadian wilderness to the southeastward and eastward of James Bay, in order to determine the direction of ice movement within the region, so that the _tracking_ of the stones already found may be carried nearer their home. The Director of the Geological Survey of Canada is giving attention to this matter, and has also suggested that a study be made of the material found in association with the diamonds in the moraine, so that if possible its source may be discovered.

With the discovery of new localities of these emigrant stones and the collection of data regarding the movement of the ice over Canadian territory, it will perhaps be possible the more accurately and definitely to circumscribe their home country, and as its boundaries are drawn closer and closer to pay this popular jewel a visit in its ancestral home, there to learn what we so much desire to know regarding its genesis and its life history.

* * * * *

William Pengelly related, in one of his letters to his wife from the British Association, Oxford meeting, 1860, of Sedgwick's presidency of the Geological Section, that his opening address was "most characteristic, full of clever fun, most imperative that papers should be as brief as possible--about ten minutes, he thought--he himself amplifying marvelously." The next day Pengelly himself was about to read his paper, when "dear old Sedgwick wished it compressed. I replied that I would do what I could to please him, but did not know which to follow, his precept or example. The roar of laughter was deafening. Old Sedgwick took it capitally, and behaved much better in consequence." On the third day Pengelly went to committee, where, he says, "I found Sedgwick very cordial, took my address, and talks of paying me a visit."

NEEDED IMPROVEMENTS IN THEATER SANITATION.

BY WILLIAM PAUL GERHARD, C. E.,

CONSULTING ENGINEER FOR SANITARY WORKS.

Buildings for the representation of theatrical plays must fulfill three conditions: they must be (1) comfortable, (2) safe, and (3) healthful. The last requirement, of _healthfulness_, embraces the following conditions: plenty of pure air, freedom from draughts, moderate warming in winter, suitable cooling in summer, freedom at all times from dust, bad odors, and disease germs. In addition to the requirements for the theater audience, due regard should be paid to the comfort, healthfulness, and safety of the performers, stage hands, and mechanics, who are required to spend more hours in the stage part of the building than the playgoers.

It is no exaggeration to state that in the majority of theater buildings disgracefully unsanitary conditions prevail. In the older existing buildings especially sanitation and ventilation are sadly neglected. The air of many theaters during a performance becomes overheated and stuffy, pre-eminently so in the case of theaters where illumination is effected by means of gaslights. At the end of a long performance the air is often almost unbearably foul, causing headache, nausea, and dizziness.

In ill-ventilated theaters a chilly air often blows into the auditorium from the stage when the curtain is raised. This air movement is the cause of colds to many persons in the audience, and it is otherwise objectionable, for it carries with it noxious odors from the stage or under stage, and in gas-lighted theaters this air is laden with products of combustion from the footlights and other means of stage illumination.

Attempts at ventilation are made by utilizing the heat due to the numerous flames of the central chandelier over the auditorium, to create an ascending draught, and thereby cause a removal of the contaminated air, but seldom is provision made for the introduction of fresh air from outdoors, hence the scheme of ventilation results in failure. In other buildings, openings for the introduction of pure air are provided under the seats or in the floor, but are often found stuffed up with paper because the audience suffered from draughts. The fear of draughts in a theater also leads to the closing of the few possibly available outside windows and doors. The plan of a theater building renders it almost impossible to provide outside windows, therefore "air flushing" during the day can not be practiced. In the case of the older theaters, which are located in the midst or rear of other buildings, the nature of the site precludes a good arrangement of the main fresh-air ducts for the auditorium.

Absence of fresh air is not the only sanitary defect of theater buildings; there are many other defects and sources of air pollution. In the parts devoted to the audience, the carpeted floors become saturated with dirt and dust carried in by the playgoers, and with expectorations from careless or untidy persons which in a mixed theater audience are ever present. The dust likewise adheres to furniture, plush seats, hangings, and decorations, and intermingled with it are numerous minute floating organisms, and doubtless some germs of disease.

Behind the curtain a general lack of cleanliness exists--untidy actors' toilet rooms, ill-drained cellars, defective sewerage, leaky drains, foul water closets, and overcrowded and poorly located dressing rooms into which no fresh air ever enters. The stage floor is covered with dust; this is stirred up by the frequent scene shifting or by the dancing of performers, and much of it is absorbed and retained by the canvas scenery.

Under such conditions the state of health of both theater goers and performers is bound to suffer. Many persons can testify from personal experience to the ill effects incurred by spending a few hours in a crowded and unventilated theater; yet the very fact that the stay in such buildings is a brief one seems to render most people indifferent, and complaints are seldom uttered. It really rests with the theater-going public to enforce the much-needed improvements. As long as they will flock to a theater on account of some attractive play or "star actor," disregarding entirely the unsanitary condition of the building, so long will the present notoriously bad conditions remain. When the public does not call for reforms, theater managers and owners of playhouses will not, as a rule, trouble themselves about the matter. We have a right to demand theater buildings with less outward and inside gorgeousness, but in which the paramount subjects of comfort, safety, and health are diligently studied and generously provided for. Let the general public but once show a determined preference for sanitary conditions and surroundings in theaters and abandon visits to ill-kept theaters, and I venture to predict that the necessary reforms in sanitation will soon be introduced, at least in the better class of playhouses. In the cheaper theaters, concert and amusement halls, houses with "continuous" shows, variety theaters, etc., sanitation is even more urgently required, and may be readily enforced by a few visits and peremptory orders from the Health Board.

When, a year ago, the writer, in a paper on Theater Sanitation presented at the annual meeting of the American Public Health Association, stated that "chemical analyses show the air in the dress circle and gallery of many a theater to be in the evening more foul than the air of street sewers," the statement was received by some of his critics with incredulity. Yet the fact is true of many theaters. Taking the amount of carbonic acid in the air as an indication of its contamination, and assuming that the organic vapors are in proportion to the amount of carbonic acid (not including the CO_{2} due to the products of illumination), we know that normal outdoor air contains from 0.03 to 0.04 parts of CO_{2} per 100 parts of air, while a few chemical analyses of the air in English theaters, quoted below, suffice to prove how large the contamination sometimes is:

Strand Theater, 10 P. M., gallery 0.101 parts CO_{2} per 100. Surrey Theater, 10 P. M., boxes 0.111 " " " Surrey Theater, 12 P. M., boxes 0.218 " " " Olympia Theater, 11.30 P. M., boxes 0.082 " " " Olympia Theater, 11.55 P. M.., boxes 0.101 " " " Victoria Theater, 10 P. M., boxes 0.126 " " " Haymarket Theater, 11.30 P. M., dress circle 0.076 " " " City of London Theater, 11.15 P. M., pit 0.252 " " " Standard Theater, 11 P. M., pit 0.320 " " " Theater Royal, Manchester, pit 0.2734 " " " Grand Theater, Leeds, pit 0.150 " " " Grand Theater, Leeds, upper circle 0.143 " " " Grand Theater, balcony 0.142 " " " Prince's Theater, Manchester 0.11-0.17 " "

(Analyses made by Drs. Smith, Bernays, and De Chaumont.)

Compare with these figures some analyses of the air of sewers. Dr. Russell, of Glasgow, found the air of a well-ventilated and flushed sewer to contain 0.051 vols. of CO_{2}. The late Prof. W. Ripley Nichols conducted many careful experiments on the amount of carbonic acid in the Boston sewers, and found the following averages, viz., 0.087, 0.082, 0.115, 0.107, 0.08, or much less than the above analyses of theater air showed. He states: "It appears from these examinations that the air even in a tide-locked sewer does not differ from the standard as much as many no doubt suppose."

A comparison of the number of bacteria found in a cubic foot of air inside of a theater and in the street air would form a more convincing statement, but I have been unable to find published records of any such bacteriological tests. Nevertheless, we know that while the atmosphere contains some bacteria, the indoor air of crowded assembly halls, laden with floating dust, is particularly rich in living micro-organisms. This has been proved by Tyndall, Miquel, Frankland, and other scientists; and in this connection should be mentioned one point of much importance, ascertained quite recently, namely, that the air of sewers, contrary to expectation, is remarkably free from germs. An analysis of the air in the sewers under the Houses of Parliament, London, showed that the number of micro-organisms was much less than that in the atmosphere outside of the building.