the relationship. These tests have been further elaborated and all tend to confirm the first results. On both tests it has been found that the blood of man and of the anthropoid ape behave in a way to indicate they are closely related, while the relation is more remote in the case of the monkeys and the lemur. Thus the evidences for evolution from the fields of anatomy, embryology and fossil study are receiving strong additional support from the field of physiology."

SUBMARINE TRACTORS TO RAISE WRECKS

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SYSTEM OF MARINE SALVAGE devised by Jesse W. Reno does not employ divers, and hence is not limited in its operation to depths at which divers may safely work. It employs a submarine tractor which moves on the seabottom and can operate at depths that would be fatal to any diver. A crew goes with the tractor and operates it, but its members remain within a large and strong steel caisson and carry on operations without leaving it. The tractor has "caterpillar wheels" and carries powerful searchlights. A contributor to The Nautical Gazette (New York) is of the opinion that this device is a challenge to the "sea's hold on sunken wealth," and that we are to witness salvage operations on a gigantic scale by its means. He begins his account by telling of the recent raising of the tug Scally, in Long Island Sound:

"A little group of men stood on the deck of a lighter moored off Whitestone Landing, Long Island Sound, last week, eagerly watching an unbroken expanse of ocean. Then these who kept vigil were rewarded for their faith and patience by seeing a number of dark objects followed by the funnel and superstructure of a vessel emerge from the waves and float safely on the surface. Immediately three tugs lying in the vicinity blew loud and triumphant blasts on their sirens, the watchers on the lighter gave lusty cheers which were echoed by spectators on the distant shore. The dark objects were the heads of pontoons used in the Reno marine salvage system, the funnel and superstructure belonged to the Coast Guard cutter Scally, which had been lying submerged in sixty feet of water for several months, and their appearance proclaimed the success and practicability of the salvage system invented by Jesse W. Reno of New York.

"There was far more involved in this demonstration than the mere raising of a sunken ship; it marked the opening of a new vista in the reclamation of wrecked vessels and cargoes. Not one new or untried principle in either mechanical or hydraulic engineering is employed, but by gathering into one coherent system known and proved processes Jesse W. Reno has answered the challenge of the sea and has devised a means for wresting from the depths the immense stores of wealth which the ocean has taken as its toll.

"During recent years many schemes have been invented for salvaging lost ships, but most of them have consisted mainly of a form of diving-suit which enabled a man to descend far enough below the surface of the sea to reach the wrecks. The most extravagant claims for these devices, however, have never gone beyond comparatively shallow water and the field of salvage has been limited to the depths at which men have been able to work. The Reno system, however, does not depend upon a diving-suit, but employs as one of its two main working units a submarine tractor which moves around at the bottom of the ocean. This tractor can descend to great depths sufficient to reach any known wreck. There is not a wreck which can hide from its powerful searchlights nor escape from its giant caterpillar wheels.

"This tractor carries a circular steel caisson seven feet in diameter and nine feet high on the inside, the whole weighing eighteen tons on the surface. Two men operate the tractor from the inside of the caisson, air being supplied by the same system as that used in submarines. Drills project from the sides of the caisson, the leakage of water through the apertures through which the drill shafts pass being prevented by stuffing boxes. The tractor is lowered to the bottom from the mother-ship, which supplies the power through cable to an electric motor inside the caisson. This motor drives the tractor belts and also operates the drills." The tractor draws up alongside the wreck, and holes are drilled through the plating of the ship, the number being regulated by

lashed so that they become an integral part of the wreck, which is towed into dry dock or beached. We read further:

"It does not require too great an imagination to understand what valuable services the apparatus can render. Around the shores of Britain and France there are approximately 1,600 ships sunk by submarines during the war, most of them lying in about 100 feet of water, and many of them carrying individual cargoes valued at over a million dollars. During the two years following the war the British Salvage Association recovered ships and cargoes valued at over $400,000,000, and all they salvaged were those lying in comparatively shallow water. Some of the greatest prizes are those lying in deep water, but easily available under the Reno system. Furthermore, it has frequently been necessary to blow up sunken vessels as dangers to navigation, but these can now be saved intact.

"It is these vessels lying in shallow water which will first claim the attention of the Reno Company, an official of which is now in England making an investigation of these war wrecks."

A 32-TON CAMERA-A camera which occupies two rooms of the Department of Interior Building, Washington, is being used by the Geological Survey to photograph maps and charts. According to The Nation's Business (Washington, D. C.):

"The lens, bellows, and copy-holder are in one room, and the plate-holder and dark room are in the other room. The camera will take a picture 1 yard square. It weighs 7,000 pounds, and is operated either by hand or by electricity. Focusing is done by means of an electrical contrivance which flashes a signal when the proper focus is reached."

Plant men, for a dozen years or more, he says, in investigating instances of cable insulation being injured by moisture, have discovered small holes bored completely through the sheathing. In recent years the trouble has reached rather serious proportions in California, and has been frequently reported in other sections of the country. We read further:

"After several years of investigation the findings of the government scientists have been announced and are contained in a bulletin issued by the Department of Agriculture under the title of 'The Lead-Cable Borer, or "Short Circuit Beetle" in California.'

"Tho known popularly as the lead-cable borer, the little bug responsible for all the damage and hubbub has a far more fancy name technically-Scobicia Declivis. According to the investigations of Dr. Snyder and his associates, the lead-cable beetle does not eat as he bores into the cable. This was determined from the fact that poisons have been impregnated into various substances in which he bored, and they never have had the slightest effect on him."

The character of damage done by the beetle is described in the government booklet in this manner:

"Damage to the lead sheathing of aerial telephone cables consists of round holes about one-tenth of an inch in diameter which extend through the lead sheathing from the outer surface to the paper insulation of the wires within. In practically every case the hole is made through the lower side of the sheath close to where the suspending ring or marline hanger supports the cable.

"In cases where the sheathing is penetrated, moisture is very readily drawn in to the wires. If the hole happens to be in the proper location a great deal of moisture enters and the cable may be ruined for 15 or 25

feet. Particularly in case of a slack cable, or those on grades, the moisture sometimes penetrates and soaks the insulation for long distances. This necessitates cutting out the cable, splicing and insulating the wires, and resheathing, which in a 600-pair cable means considerable skilled labor . . .

"It was about this time that the Department of Agriculture stept in with an offer of help. A large quantity of California oak known to contain eggs of Mrs. Declivis were shipped to the forest insect field station of the Bureau of Entomology at Falls Church, Virginia, and were placed in glass cages. Specimens of cables were prepared by engineers of the C. and P. and were suspended from the tops of the cages.

"When it was seen that the beetle had no inclination to touch the cable, metal sheathings were wrapt around wooden logs into which beetles had already bored. The entomologists knew that within a year newly grown adults would be eager for a glimpse of the world and would try to bore themselves out.

"After those young beetles had finished with the sheathing, it looked like a well-worn sieve. Sheet lead of various alloys, including antimony and tin, were tried, but none seemed able to stop the bugs when placed as a barrier to their progress.

"In California, actual working cables were used in several tests. Small cages were built around parts of the cables and numbers of beetles placed within. On the smooth surface of the cables the beetles made few attacks, but where the lead sheathing touched any other surface, such as the metal ring suspending it, the bugs made numerous bores. In the words of the government report: "Practically all of the boring is done near the point of contact of the cable and the rings which suspend the cable from the messenger strand. The authors believe that the beetle bores the cable because it finds itself closely confined between the cable and the suspending ring, but they do not believe that it can be proved." It would seem that no real remedy has yet been found, as the writer continues in a semi-hopeful vein:

"The means of eventually stamping out the trouble possibly lies in the adoption of a new type of suspension ring, made of flattened steel wire stock which has been galvanized and which makes a joint with the cable without giving the beetle a firm foothold.

"Mr. and Mrs. Declivis, however, continue their existence undisturbed. Boring into telephone cable is a side-line with them anyway, and so long as no one tries to prevent them from boring in and out (or out and in, if you like) of oak trees they probably will start no organized resistance. We sincerely hope they will not, for they might put up a tough fight. The report tells us that the beetles can multiply at the rate of more than a hundredfold a year, so it appears that the thing to do is to use diplomacy; we want no rough stuff with an army that grows at the rate of 10,000 per cent. annually.

COTTONLESS COTTONWOODS—Regarding an article in our issue of May 5 on the prevention of the annual "cotton" pest, from the pistillate cottonwood tree, John Bristol, of Moab, Utah, writes as follows:

"A far simpler method than spraying has been tried and has proved its worth. All that is necessary is to bore a fairly large hole, an inch or more in diameter, into the bole of the tree. This should be done early in the spring, before the tree blooms. The hole should penetrate to the heart of the tree, and it should be bored so as to slant downward. When the heart of the tree has been reached, pour a pint or more of plain kerosene into the hole and the tree so treated will shed no cotton that season, at least. The simple fact of boring the hole to the heart of the tree will stop the cotton, but the application of kerosene makes the remedy doubly sure. This method does not in the least injure the tree. Here in Moab we have cottonwood trees which have attained the altitude of real giants. So far do their branches reach out that in places they form an arch over the streets of the town. You will readily see that to spray these giants in their native habitat will assume the proportions of a formidable task. However, all Moabites agree that the annual 'cotton' crop of the trees is nothing less than a pest."

"By June of 1918 most of the young beetles at Falls Church had grown to the adult stage and were emerging from the wood. They made themselves fully at home and many began to bore into the wooden parts of the cages. But they didn't touch the cable; they ignored it entirely, as if suspecting a trap.

HOW FAR CAN MY RADIO SET RECEIVE?

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HIS SEEMS TO BE a universal question, ever since radio came into popular use, we are told by Kenneth Malcolm, writing in Radio World (New York). And it is a question that can not be answered by examining the set alone. If fixt and ideal conditions were available, the answer could be given with a fair degree of accuracy, at least theoretically, but practically many variable factors must be taken into consideration. Identical sets, with antennæ in exact copy, located but a block apart, may give widely different results one getting the most distant stations and the other nothing but the locals. We read:

"As an illustration of what is meant by variable factors, let us ask how far a locomotive whistle can be heard. Immediately the answer might oecur: 'It depends upon the power of the whistle.' Yes, that is true, but it also depends upon the nature of the Surrounding country, the condition of the air, the direction of the wind, the direction the train is traveling, and the sensitiveness of the ear of the listener. In wide-open country the sound could be heard much farther than in thickly wooded country or in the city. It could be heard farther if the air was clear and the wind blew in the direction of the listener, also farther if the listener's ears were very sensitive and the locomotive was approaching instead of going in the opposite direction. Any combination of these factors would produce different results.

Waves

Jumping

A Gap

Waves
Following

The Contour

land, Mr. Malcolm tells us, the degree depending to some extent on relative dryness of the land. Then, too, there are fewer obstacles in the way when the waves pass over water. Ships at sea copy "press" many times over a distance of 1,500 miles with a comparatively ancient crystal set. He goes on:

"The condition of the atmosphere is a great factor that can not be disregarded, for this is the operator who can at will switch you to either 'local' or 'long distance.' It was the atmospheric conditions that enabled most of the long-distance records to be made and broken. When you can get Davenport one night and only

"In radio work we have even more factors to contend with. First of all comes the power of the transmitter and the sensitiveness of the recriver. Under given conditions an increase of power or an increase in the sensitiveness of the receiving set will give a proportional increase in range. A broadcasting station may have a maximum range of 1,500 miles; but this distance iscovered only with a two-stage radio-frequency amplifier set at the receiving end. A single tube set might hear it only 200 miles and a crystal set only 30 miles. Then, again, the reverse is also true; a single tube set might be rated at 500 miles, but only from a station with one kilowatt rating A 500-watt station might be heard only one-half that distance.

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"Next in importance comes the immediate environmentpossibly this comes even before power and sensitiveness. aerial situated between tall, steel frame structures will not bring in as good results as one that is located in the open, for the grounded steel frames absorb a large part of the energy before the waves reach it. It is also manifest that steel buildings affect the quality and range of the waves from a transmitting station. station that promised to be one of the best in the city, had to be dismantled, or at least used only for experimental purposes, because the steel in the building in which it was located, and in neighboring buildings, had the tendency to distort the wave, thereby preventing faithful transmission.

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Pittsburgh the next night, you can in most cases blame it on the weather. Clear air is the best air; and water and dust particles are detrimental, as they tend to absorb part of the energy of the advancing waves. Reception can not be carried on as well in the daytime as in the night because the sun's rays ionize the air particles and render them conductive, hence absorbent.

"Considering all the variable factors it is not quite fair to ask how far a certain set can receive. The only real way to find out is to try it under the actual conditions in which it will be eventually used. Even then you will find that every set has what we might call a reliable and variable range; one that can be depended upon under all conditions, and a second that will work only when things are most favorable.

"It may be inferred that a given receiving-set will have its greatest range when the air is clear, at night, over water, and the transmitter is of the highest power and in the most favorable local environment.

"If your set does not give quite as satisfactory results as you might expect, don't condemn it immediately, but look around and see if there is not some condition which you might better. Possibly a little change in the location of your

aerial might transform a failure into a success. When on the hike keep to the water, the open spaces, and the mountain-tops and stay out of the walled-in valleys."

WHY DOES BREAD GROW STALE?-Old ideas of how bread stales are overturned by the Food Research Institute, established at the suggestion of Herbert Hoover, in its first publication just issued from its headquarters at Stanford University. The report points out the wholesomeness of the stale loaf, shows the waste produced by present bakery practises, and urges further investigation of why some bread keeps better than others. We read in Science Service's Daily Science News Bulletin (Washington):

"What probably occurs is that much of the moisture in the bread is held by the starch which has been gelatinized in the baking. As the loaf comes out of the stove, this starch jelly distributed through the bread contains all the moisture it can hold. As the bread cools, the starch gives up some of its moisture and this moisture is absorbed by the other constituents of the loaf, changing the crust from a brittle material that crunches between the teeth to a soft and pliable one, while the gluten of the crumb is given a toughness and firmness which as fresh bread it did not have. The bread becomes stale at low temperatures, and this accounts for the fact that bread when stale, but not dry, can be freshened up by heating. The process is reversed and the starchjelly reabsorbs the moisture from the other bread constituents."

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SECOND STORIES IN POMPEII

zontal layers, with minute attention to details. As objects are found they are photographed and their position accurately noted, so they may be replaced when the whole house is restored to light.

Walking down the 'Street of Abundance,' along which the new excavations are being made, on the perfectly preserved sidewalks, worn smooth by the sandals of the ancient Pompeians,

of work are too fine for pick and shovel. It is a vastly different thing from walking into an Egyptian tomb and removing the stores kept intact for ages. The investigator's processes are almost as delicate as the goldsmith's, and the consequence is the uncovering of frescos, of the roots of trees and even the fibers of fabrics. Tools smaller than needles are used, says Arnold Cortesi in the magazine section of the New York Times. Workmen are "trained to notice where the lapilli change color, for there it means that something existed which was burnt by the flaming lava." By such means traces of blankets have been found on beds and of washing stretched out to dry. We are even told that

"The workmanship has been so perfect as to allow the rotted roots of trees and even of shrubs to be extracted from the gardens, then to pour liquid plaster of paris into the holes thus left in the ground and to obtain plaster casts of the roots. Thus was Spinazzola able to recognize the vegetation and to form a clear picture of what the gardens must have looked like.

"It is ten years since the Italian Government approved Spinazzola's ideas for the excavations, and since then he has disappeared completely from society, buried in the Pompeian ashes. His method of procedure is not the old one of digging a pit, deepening it till a floor was reached, and then widening it sideways until walls were reached. Spinazzola digs in hori

the impression one gathers is not of a city turned into stone 1,800 years ago, but of a town whose inhabitants abandoned it a few years back and whose houses are gradually crumbling. Even this impression, however, must be revised when one sees how fresh are the paintings on the walls and how recent seem the electoral and amusement posters and the scribblings of boys which cover the walls."

Competent archeologists of the past are proven quite wrong in their deductions from appearances hitherto revealed. For example

"The writings and reconstructions of studious and competent archeologists, such as, for instance, Augustus Mau, had led one to expect streets in which the houses had no external windows-only a door and, perhaps, a few barbiconsin which balconies were rare, in which, in other words, houses were nothing but big boxes with roofs leaning toward an inner court, into which the only windows of the house opened. Even the existence of second floors was considered problematic or, at any rate, very unusual.

"But then one sees the 'Street of Abundance'! Two-story houses everywhere, with far projectWindows ing balconies and windows, windows everywhere. with iron gratings on the ground floor, windows with marble or stone frames, carved or plain, white or colored, windows to suit all tastes. Balconies and loggias, large and small, with graceful pillars or without, here, again, to suit all tastes. And paintings, and shop signs, and posters, and scribblings on the walls. Everything is still there.

"The private houses are, perhaps, the least interesting part of the new excavations, because they are all more or less alike in the richness of their interior decorations, in the number and size of the rooms and even in the disposition of these. They all have a straight and narrow corridor, of the width of the front door, leading to the 'atrium,' or courtyard, which is generally surrounded by a cloister. The rain-water from the roof of the cloister collects in an 'impluvium' or cistern, in the center of the atrium. From the atrium doors open into the other rooms of the house. The largest room is usually the 'triclinium,' or diningroom, in which there generally can still be seen the stone blocks which, covered with mattresses, served as couches during meals. Adjoining the triclinium, generally, is the kitchen, and next to the kitchen the bathroom.

"The luxuriousness of the bathrooms is amazing. In one case two rooms compose the bathing suite. One is the 'apoditerium,' or changing-room, and the other the 'caldarium' or bathroom proper. The caldarium had its walls and floor made of special hollow bricks, through which hot air circulated.

Both the air and the bath-water were heated by a 'hypocaustum,' as was called the special grate placed in the near-by kitchen. Bedrooms and spare rooms, have also been found, remains of beds and bed-clothing being visible. The beds were either like our modern couches, that is, with backrests along three sides, or else in the form of alcoves set into the walls and hidden by curtains. Additional rooms of smaller importance are also to be seen, such as coal cellars, larders and tool-sheds. "All the rooms are magnificently decorated. Frescos adorn all the walls, from cellars to the outside of the houses, and with such a richness of color and such a vividness of tone as to leave one gasping. The paintings generally divide the walls into panels, on each of which is represented a scene of movement. Between the panels are festoons of flowers and fruits. The Hellenic influence of Pompeian art is very noticeable, especially in the frescos, a majority of which represent scenes from Homer's 'Iliad.' A very interesting and hitherto unknown architectural characteristic has been discovered in the most recent excavation 3. The roofs of the houses were made of tiles and did not end flush with the sides of the walls, but overhung by the length of several tiles, thus affording the sidewalk protection from sun and rain. By this discovery significance has been given to the Latin word 'pluma,' which is often found in Latin writings, always in connection with houses and walls, but whose exact meaning had hitherto remained unknown. Obviously 'pluma' means a projecting cornice, whose object was similar to that of the canvas awnings which protect modern shop windows from the fierce rays of the sun."

(and apparently very proud of it), pointed the fact out by adorning his shop with a painting of Romulus, the founder of Rome, on one side, and of Aeneas, the chooser of the site where Rome was built, escaping from Troy with Anchises and Ascanius, on the other. Similar paintings are found outside all shops, varying in beauty and artistic value.

'Another discovery of great value is a public laundry in perfect state of preservation, which had just been completed when it was engulfed in the general ruin which overtook Pompeii. That it had only just been completed is proved by heaps of mortar and stone masons' instruments which were found on the side

Pompeii is found full of shops and bars that are astonishingly like our modern ones. A shop where small articles of glass, bronze and iron were sold shows that these various wares were exhibited on stands in front, for we read:

The existence of these stands can be seen by the marks their repeated removal each night and replacement each morning made on the sidewalk. These same marks reveal that some of the -hops occupied more than one room along the front of the house, thus affording some sort of a parallel to the big department stores of modern times. One shop, which was closed at the time of the disaster, has provided the means of ascertaining how the shops were shut up at night. The ashes belched out from the erater of Vesuvius, piled up against the door, and, tho the wood was partly burned at the time and has partly decayed since, the ashes hardened and retained the shape of the door. A plaster of paris cast was taken, which reveals that the shop was shut by means of vertical boards which ran in slots carved in the sill and the architrave of the door. These boards were then secured by means of a long iron or bronze bar which could be locked in position.

"These shops had signs outside, which by their variety and bright colors sought to attract the attention of the passers-by. These signs were works of art and were, apparently, constantly being changed. A dyer's shop has on both sides of the door two of the most wonderful frescos in Pompeii. On the left there is a temple of yellow marble, from which Mercury (the god of commerce) steps out hurriedly (as can be seen from his flowing robes) carrying in one hand his sacred rod and in the other a bag. On the right there is a wonderful picture of Venus standing on a royal chariot drawn by four immense elephants. She is clothed 17 a cloak, blue as the sea she was born from, and on her head she wears a high golden diadem. The vividness of the colors and the technique of the execution are amazing. These frescos, now valued so highly, were in those days nothing but ordinary shop signs, which would be changed as soon as they became soiled by passers-by rubbing against them or scribbling on them. A coat of whitewash was applied and a new fresco painted on top. "Two more particularly interesting frescos appear outside the shop of a man who, not being a Pompeian but a Roman

walk outside. Here are cisterns and tubs of all sizes and shapes, with an extremely ingenious system of water-piping."

"PUTTING OVER" POETRY-Miss Edith Sitwell, an English poet, some of whose verses we have quoted, lately gave a recital of her own verses in London and used a "Sengerphone" to blast it through to the audience while the reciter was concealed behind a screen. The curtain, says the London Star, represented "a Futurist façade, with a face in the middle through the mouth of which protruded a speaking-tube."

"It was not an ordinary face, mark you, but had a line down the middle, and the right half was white and the left half redI can not pretend to interpret the symbolical significance of this, but doubtless it is very deep indeed.

"Miss Sitwell is accused by her critics of specializing in 'obscure poetry.' I will not usurp the functions of literary critics and pretend to say whether the accusation is just. At any rate, the verses when spoken through the Sengerphone in strict time are not easy to understand.

"The Elect-to show how very elect they are-encored several, which I could not understand at all, notably 'Hornpipe' and one with the delicate title 'Ass Face.' A voice explained that it was about Beavers, but even so that conveyed nothing to my unelect intelligence."

The Manchester Guardian observes:

"Those who take up the megaphone must be judged by their choice. Either they want to startle us, by the way in which their verse is presented, which is a tacit confession that there is nothing very startling in the verse itself; or else, in Goldsmith's famous phrase to Dr. Johnson, they want to make little fishes talk like whales. It won't do; however large they may sound, the little fishes merely look smaller than ever at the other end of their magnificent funnel."