WE SHOULD HAVE INVENTED THE ROTOR POWERED SHIP

WE SHOULD HAVE EXPECTED the rotor ship to be an American invention, says Dr. Edwin E. Slosson in Science Service’s Daily Science News Bulletin (Washington) ; first, because the principle involved is the same as our pitchers employ in putting the curve on a baseball; and, second, because this force has been thoroughly studied in American laboratories of aero-dynamics. He goes on:

“A recent technical paper by Elliot G. Reid of the Langley Memorial Aeronautical Laboratory is devoted to’ tests on rotating cylinders’ and gives the formulas by which the force can be calculated and photographs showing how air currents behave in passing around a cylinder. If the cylinder is stationary, the wind divides and goes by equally on both sides, producing no effect except a push on the windward side. But if the cylinder is revolving the wind receives different treatment on the two sides. On the side of the cylinder where the rotary motion is in the same direction as the wind, the air is helped along and speeded up by the friction of the surface of the cylinder. Consequently, the air-pressure is reduced on this side and a sort of suction is formed. On the side of the cylinder that is turning against the wind, the opposite effect is produced by the friction. That is, the flow of the air current is impeded, the air is comprest and its pressure on the cylinder is increased. The net result of diminishing the pressure on one side and increasing it on the other is to produce a push acting on the cylinder at right-angles to the wind, and it is this force that propels the Flettner boat.

The power of this cross-wind force depends upon the velocity of the wind, the height and diameter of the cylinder and its speed of rotation. The greater these are the stronger is the power developed. The Langley Laboratory finds that this force appears suddenly when the speed of the surface of the rotating cylinder rises to half that of the wind, and that there-after the force increases steadily with the speed until the surface is moving twice as fast as the wind, or faster.

The experiments suggest that if the rotating shaft is made in the shape of a Greek cross instead of a smooth cylinder a greater cross-wind force may be produced, tho it requires more power for rotation. The National Advisory Committee for Aeronautics has been engaged for a year in the investigation of the possibility of equipping airplanes with rotating cylinders, so as to utilize this cross force to impart a lift to the machine instead of depending wholly on the angle of the winds. But neither our baseball fans nor our aviation experts have applied the principle to ship propulsion. So Anton Flettner has a free field, and it his invention works as well as the German papers claim, he may appear before long in one of our ports with the ten-thousand-ton sailless ship that he plans to construct for transatlantic trade. It will be as strange an apparition as the submarine that bobbed up at Baltimore loaded with German dyes and drugs during the war, and it will be much more welcome.”

Source: The Literary Digest for February 14, 1925

Advantages of the Hoover Vacuum Cleaner

You have to beat rugs to get them clean.

Nothing very new about that, is there? You’ve heard it a thousand times. If you’ve ever kept house you know it’s true.

Because it is true, it wasn’t enough that The Hoover should whisk up dust and lint from the surface of carpetings.

No; so long as it was the deeply embedded dirt that did the damage, The Hoover must be designed to get that, too.

What better method of getting it than to apply the time-tested principle of beating— of jarring the buried dirt to the, surface so it would be suctioned away?

Such is the reasoning behind The Hoover, which as everyone knows is the electric cleaner that beats, as it sweeps, as it cleans.

Such is the practical common sense behind the now-famous principle of “Positive Agitation,” which is beating reduced to an exact scientific process.

Such beating, instead of being concentrated in a few violent strokes as with the carpet-beater or broom, is modified by The Hoover into a series of swiftly repeated air-cushioned taps. This is accomplished by means of a totally new appliance—the exclusive and patented Hoover Agitator illustrated here.

Suction lifts the rug from the floor and floats it on a cushion of air while the Agitator gently flutters out all the embedded grit.

Then strong suction draws all this dirt into the dust-tight Hoover bag.

Simple, isn’t it? Efficient, too. “You have to beat rugs to get them clean.”

The difference between The Hoover and a vacuum cleaner is that The Hoover does beat them—”Positive Agitation” being a feature of the celebrated Model 700 Hoover and of the lower-priced Model 543 Hoover as well.

Authorized Hoover Dealers will make you an allowance on your old cleaner, delivering you a new Hoover on easy payments. Cash price, the Model 700, $75.00 or the Model 543 Dusting tools, $12.50. Prices slightly higher west of Rockies and in Canada.

THE HOOVER COMPANY, NORTH CANTON, OHIO
The oldest and largest maker of electric cleaners. . . The
Hoover is also made in Canada, at Hamilton, Ontario

The HOOVER
It BEATS … as it Sweeps as it Cleans

Hoover Advert from The Literary Digest for October 29, 1927

COMING: THE FISH-OIL MOTOR

The possibility of farming the sea for motor-fuel, after all the oil and gasoline are gone, is indicated by studies of the use of fish oils and other animal oils as motor fuels reported to the French Academy of Sciences, in Paris, by Messrs. Georges Lumet and Henri Marcelet. Says Dr. E. E. Free’s Week’s Science (New York):

“Using engines of Diesel or semi-Diesel type, which run ordinarily with one kind or another of petroleum oil, the French investigators were able to obtain quite successful operation using several kinds of oil from fish. In addition, they determined the heating value of definite volumes of these oils and discovered them to be not seriously inferior to mineral oils. Not even any bad smell is produced by the use of fish oil in the engine, a happening which might well be expected when one remembers the unpleasant odors of the oils themselves. The fishy smell of the oil is evidently destroyed during the combustion in the engine. Altho engines of these Diesel types are not now made in small enough sizes to be used in automobiles, this is a development confidently expected within a few years. When such small Diesel engines have become available, oil from the enormous numbers of fish which might be caught in the world’s oceans may constitute a useful addition to mankind’s supply of fuel.”

Source: The Literary Digest for October 29, 1927

The New Orthophonic Victrola Record Player

THINK of having America’s greatest dance-organizations at your beck and call! Orchestras that would cost a small fortune to engage for a single evening! Through the new Orthophonic Victrola and the amazing new Orthophonic Victor Records, you can bring these selfsame orchestras right into your home. Exactly as you would hear them at the smart supper-clubs and hotels!

Listen to that crooning saxophone carrying the melody . . . the plinkety-plank of the banjos underneath beating a rhythmic accompaniment. Now the clarinet with its toe-teasing cadences. Now the guttural “bong” of the bass sax or the mellow “oomp” of the big brass tuba. Who can resist dance music like this?

The music you want, whenever you want it.

Not only dance music but all kinds of music are yours whenever you wish through the Orthophonic Victrola . . . reproduced with a clearness and fidelity to the original that is simply unbelievable. Voice has all the inflections, the mannerisms, the personality of the singer. “Matched impedance,” the new, scientific, Victor-controlled principle of smooth sound-flow, is responsible for Victor’s matchless tone.

The new Orthophonic Victor Records are an achievement comparable to that of the Orthophonic Victrola itself. They have a new fulness, a new depth and power. They are recorded by microphone, and made from an improved material which eliminates all foreign noises. They play on any instrument . . . and vastly improve its playing quality!

Until you hear the new Orthophonic Victrola play the new Orthophonic Victor Records, you cannot have the remotest conception of the thrill this amazing combination will bring you, day after day, year after year. See the nearest Victor dealer today. There are many beautiful models of the Orthophonic Victrola, from $95 to $300, list price. Silent electric motor ($35 extra) does away with winding. You play . . . and dance!

Source: The Literary Digest for April 2, 1927

TRAFFIC RULES FOR AIRCRAFT

LIKE THE RULES FOR AUTO DRIVERS are the traffic rules for aircraft just issued for the first time by the Aeronautics Branch of the U. S. Department of Commerce, reports H. C. Davis in The Popular Science Monthly (New York). Reading them, he says, it is easy to imagine the day when the air will be thick with airplanes, and traffic officers may direct the streams of flyers from captive balloons. Now right of way and license numbers belong as much to the air as to the motor road, as set forth in the Government’s new rules. He goes on:

“First rule of all, you must have a pilot’s license—without this you can not take the air, unless you would risk a $500 fine. There may be as yet no ‘motor cops’ of the air to blow a whistle and shout, ‘Pull over to that hill —let’s see your license!’ but it is well to carry on your person the certificate that proves you have passed an official pilot’s examination.

“A simple test is all that is required for a ‘private pilot’s’ license—one who flies for pleasure, not for pay. In figure 8′s, you circle two pylons and make several landings. Then a written examination proves you know how an airplane engine works; that a plane in distress at night fires a succession of Very lights; that a seaplane alighted in a fog must use a fog-horn. Your test is less severe than that for ‘industrial pilots,’ who carry commodities, or for ‘ transport pilots,’ who carry paid passengers.

“Now you may fly, but take care that you observe the ‘rules of the road.’ See that plane about to cross your path, just emerged from the white cloud bank on your right? You must wait to let him by; he has the right of way. A moment, and he is past; the ‘road’ is clear. There is no speed limit. Without warning, a plane thunders straight toward you out of the mist ahead. Coolly you swerve to the right, and pass him.

“Now you are overtaking another craft—the letters on his tail are easily visible. Pull over your rudder, sharply!—for you must give him plenty of room as you pass on his right—at least 300 feet, the regulation is. He might strike a treacherous air current and be hurled against you if you were near him. Throttle wide open, you go by.

“You decide to alter your course. You turn to the left, dive through a cloud, and swoop down to a lower level. There, almost beneath you, is a field black with people and lined with parked cars. Don’t go below a thousand feet; that’s the safety limit for an open-air crowd. A balloon ascension is in progress; the balloonist has just left the ground, and is wobbling skyward in his spherical ship. Turn out as you approach him; the right of way is his,

“A graceful landing ends your day’s flight. Home again, there is one thing more you must do. In a log that you keep for the purpose, make a brief record of your flight. Every three months you will send a duplicate of this log to the Secretary of Commerce at Washington. It must contain, also, notes of any repairs you have made on your plane, of the engine’s running time, and of the result of the inspection you are required to make before each flight. Thus the Secretary has at hand the condition of every licensed plane in the country.

“Like an automobile, every plane must now be registered and carry a license number. Huge figures painted on the wings and rudder serve as license plates, and are visible from above or below and from either side. A letter prefix signifies the airplane’s class. ‘P’ indicates a private craft, flown for pleasure; ‘C’ designates a commercial plane, while aircraft owned by States or cities are marked with an ‘S.’ U. S. Government planes carry special letters, according to their department.

“So an air pilot nowadays may lose his license because some one ‘took his number.’ If he violates any of the air traffic rules, his certificate may be suspended or taken away.”

Source: The Literary Digest for April 2, 1927

DOCTORS STUDYING THE COMMON COLD

SCIENTIFIC interest in a disease is apt to vary directly with its rarity, remarks The Lancet (London), so that minor maladies, and in particular the common cold, do not receive that attention which their prevalence would appear to warrant. Of recent years the common cold, however, has been studied more assiduously and in particular from the standpoint of prevention. Dr. Leonard Hill and Dr. Argyll Campbell devote a chapter in their new book on “Health and Environment” to the cause and prevention of “colds.” Says The Lancet: –

They summarize the supposed causes under five headings: chills and drafts, certain conditions of the weather, irritation of the respiratory mucous membrane, infection, and bad ventilation. Each of these supposed causes is then discust in turn. Exposure by itself will not cause “colds” in healthy individuals, as is shown by the immunity to these disorders enjoyed by Arctic explorers and fishermen at sea. If, however, a person is already infected there appears to be some slight derangement of the heat-regulating mechanism, so that he feels a draft of cold air more easily than a normal, healthy person and attributes a “cold” already “on him” to this cause. Cold, dry weather and strong drying winds do not favor epidemics of “colds,” while unfavorable weather conditions, such as a high relative humidity of the atmosphere with a variable temperature, certainly do. Irritation of the respiratory mucous membrane by dusts and chemical irritants is also a cause of “colds,” while a certain section of the community appears to suffer from a nervous derangement of the nasal mucous membrane, so that sudden changes of temperature and atmosphere may produce an acute paroxysm. While “infection is not the whole story,” there is no doubt about the importance of this as a cause of the common cold, and such factors as closeness of contact, duration of contact, and general conditions of ventilation vary for this as for other bacterial infections.

In the opinion of the authors, bad ventilation is the commonest cause of “colds.” Warm, stagnant air produces a congested, swollen appearance in the nasal mucous membrane, which becomes covered with thick secretion and affords a weak spot for bacterial attack. In cool air, on the other hand, the membrane is pale and taut and well moistened with secretion. To quote further:

Added to the hot air so often present in the upper layers of a badly ventilated room is the occurrence of cold air near the feet. Thus “cool breezes blowing round the head, the radiant heat of the sun, and a warm ground to stand on are the ideal outdoor conditions.” The reverse of this which produces cold feet and stuffy heads is said by these authors to be present in the House of Commons! If these elementary facts about ventilation were appreciated, a great many “colds” would be prevented. Dr. Russell L. Cecil, in a little popular book on this subject, emphasizes this, pointing out that the “non-contagious cold” largely depends upon the condition in which we keep our nasal mucous membranes.

Besides dealing with the more common methods of treating “colds,” Dr. Cecil describes the chlorin treatment, in which dilute chlorin gas is inhaled by patients. This method, based upon the fact that no cases of influenza occurred among the workers in a chlorin plant during the epidemic of 1918, seems to have a certain amount of vogue in America, and Dr. Cecil speaks well of the results. The relationship between influenza and the common cold as suggested by this therapeutic measure is an aspect of “colds” which is especially dealt with in a review of the literature on influenza and the common cold by J. G. Townsend, published by the United States Public Health Service. It is claimed that the association between influenza and minor respiratory disturbances, especially that known as the “common cold,” is “more intimate than has been recognized or conceded.” The Public Health Service arranged in 1923 to receive fortnightly reports from 10,000 persons in the United States as to whether they had suffered from any of these minor respiratory disorders during the period in question. The final analysis of the material thus collected may help to elucidate the problem.

Source: The Literary Digest for September 12, 1925

A BRITISH ARCHITECT ON THE AMERICAN APARTMENT

JUST what the American apartment house is and how it fits in with our national social life is set forth in a report made by a British architect, G. Topham. Forrest, on “The Construction and Control of Buildings and the Development of Urban Areas in the United States of America.” This survey, as explained by Alfred C. Bossom in the New York Times, was made at the instance of the London County Council, to which Mr. Forrest is the chief architect, and was undertaken for the purpose of seeing what ideas in architectural economics, as carried out in this country, could be utilized in the British metropolis and in other cities of England. Says Mr. Bossom:

Mr. Forrest was especially imprest with the adaptability of American architecture to climatic conditions and to the environment. He is more confirmed in his belief that the skyscraper, as we call it, is not for London. As he so clearly states, most American cities are further south than is the city by the Thames; New York, for instance, is 700 miles further south than is London. The result is that in the cities of the United States the rays of the sun are at a far greater angle, and no matter how tall the apartment house or skyscraper may be, the rays can be suffused for a greater part of the day through American buildings. The average width of London streets is only twenty-eight feet, while in American cities many streets are 100 feet wide.

Under the zoning laws which Mr. Forrest found in effect in more than 500 municipalities, the first line of the roofs or cornices must not be taller than is the width of the street on which the buildings face. This gives the American building the advantage. Under the old common law in London owners are prevented from shutting off the light and air of their neighbors, so it is impossible for London to have such towering structures as obtain in this country.

It is interesting to note that Mr. Forrest recommends that London get the benefit of all the height it can by employing the set-back method of construction which has become such a feature of American municipalities. England had this idea back in the days of Queen Elizabeth, but, as the English expert says, it was rather more of an ideal than an actual method. Owing to the absence of soft-coal smoke in overbearing quantities in New York, and the general freedom from fog, Mr. Forrest found that the interior corridor or hallway, without any windows, was employed with satisfaction in American buildings. This is made possible by glass-paneled doors and glazed transoms, which would be of little use in London.

Mr. Forrest declares that the standard of living, generally speaking, is higher in America than in Great Britain, and that what in America would be termed an apartment for the working-class would in England be considered in many respects superior middle-class accommodation. To quote further:

He does not think that America is so far advanced in the evolution of internal planning and layout as England is, with perhaps three exceptions, being, the appointments of kitchens; the appointments of lavatories, bathrooms, and other sanitary arrangements; the layout and treatment of the courts and open spaces about buildings.

It must be remembered, however, that such things necessarily imply a larger expenditure than is usually available in England in these items.

Mr. Forrest is imprest with the skill with which new housing accommodations are provided in American cities by building higher tenement dwellings to take the place of those which have been torn down to widen streets, or provide parks or to make neighborhoods more accessible to light and air.

The advantage enjoyed by the American housewife over her British sister receives appreciative acknowledgment from this discriminating visitor. As we read:

He states that American building development gives a great deal of instruction, saying that in the apartment buildings every apparatus is provided which can eliminate the labor of the housewife. In the apartments he inspected he found many such labor-saving devices incorporated, such as built-in ironing-boards, fitted dressers, installations for vacuum-cleaners, polished hardwood floors and wainscots, terrazzo-paved corridors, gas-fires, installations for the supply of hot water and other heating.

Mr. Forrest noted that these add to the utilities and amenities and thereby to the rentable value of the apartments. He suggests, so far as would be remunerative, that such modern accessories be incorporated in London dwellings, and that in designing such dwellings, the possible subsequent addition of such fitments be kept in mind.

As the London County Council has wide powers, and controls certain properties on which it can erect model houses and apartments, it is likely that the capital of the British Empire will soon have many flats and apartment houses planned as to their conveniences in accordance with the American idea.

Source: The Literary Digest for September 12, 1925

SOUNDS TOO HIGH TO HEAR

SOUND-WAVES of too high a pitch to affect the ear have been produced and are likely to prove useful, we are told by an editorial writer in The Electrical World. Such waves, of course, are not sound in the strictest sense, for sound-waves are due to vibrations within the audibility range of human beings. This audibility ceases, for purely physiological reasons, at somewhere between 10,000 and 20,000 cycles per second, but there is no reason why such longitudinal vibrations of much higher frequencies could not be produced, propagated and received by means of suitable detectors. We read:

In La Revue Hydrographique for November, 1924, there is a description of complete apparatus for sending and receiving such supersound-waves under water at frequencies between 40,000 and 100,000 cycles per second. The apparatus is purely electrical, quartz and a three-electrode oscillating vacuum-tube being utilized.

Probably in time such ultra-audible waves will become of increasing scientific and practical value, and engineers should turn their attention to possible useful applications. As such, the following are within possibility: (a) Sounding of the ocean-bottom and of river-beds for geological and hydrographic purposes, navigation, laying of cables, etc.; (b) location of other vessels, icebergs, shore-line, etc., in fog or at night; (c) killing of fish, with possible extension of the method of extermination of insect pests; (d) improvement in hearing of deaf persons while the ear-drum is being agitated by ultra-audible waves; (e) extension of the range of oral communication by using supersounds as carrier waves; (f) determination of the speed of a rapidly moving object, for example, a motor-vehicle, for proving a speed law violation, etc.

Source: The Literary Digest for September 12, 1925

EIGHT MAXIMS FOR REAL ESTATE OPERATORS

HOW to make money handling real estate was recently comprest into eight maxims by W. Burke Harmon, a well-known New York realtor, and reported as follows by the New York World:

1. Never buy for cash. The successful operator invests just as little of his own funds as possible, glad to pay 6 per cent. interest for the use of money that he expects to bring profit. And mortgage interest is deductible from your income tax.

2. Buy when others aren’t buying freely—don’t wait for a boom.

3. Buy property monopolistic in character that will increase in value because it can’t be exactly duplicated, such as water-front near a great city or a business corner in a thriving neighborhood.

4. Buy where things are going to happen in the future, not where the neighborhood is built up and changes are unlikely.

5. Don’t take things for granted, such as the statement that bridges make high values or that proximity to a railroad station is an asset. Transportation facilities make values, but not necessarily for property almost on top of bridge or station.

6. After asking questions and comparing values in the neighborhood and judging all future possibilities, then have the courage of your convictions to stay by your guns.

7. Know when to sell—you never get poor taking a profit, but don’t sell until you are convinced values have approached a temporary peak at least.

8. Don’t retain indefinitely property that is unimproved. Either sell or put a building on it that will produce enough to pay taxes and carrying charges.

Source: The Literary Digest for July 23, 1927

BRITAIN’S NEW SILVER CURRENCY

SOME ten months ago the price of silver rose to a phenomenal figure in Great Britain and the authorities felt considerable anxiety lest people should be tempted to melt down the silver coinage in order to obtain silver bullion from it. Whereas in prewar days the shilling had an intrinsic value of about eightpence, a point was reached in 1920 where the shilling became worth more than its currency value. The tears tor the currency proved groundless, because silver did not remain very long at the abnormally high figure. Moreover, the prohibition against melting down was sufficient check on any attempt to withdraw the silver currency from circulation and convert it into bullion. Nevertheless, the Bankers Trust Company of New York tells us in one of its bulletins, the decision to produce a new coinage of lower intrinsic value has been persisted in, altho the immediate cause has to-day vanished.

So now— The British Mint is issuing a new silver currency, half silver and half alloy, consisting of 500 instead of 925 parts fine silver to the 1,000. The latter has been the authorized quality since the reign of Queen Elizabeth.

In course of time the present silver will be withdrawn from circulation and this new coinage will replace it. The currency can not be used in payment of foreign debt and is intended only for use as small change in England.

It would be quite incorrect, we are told, to say that the British Government is making any real profit on the transaction, as some people assume naturally, for it bad to buy high-price silver for replacement purposes. It is also pointed out that the cost of production has increased. That means that “the cost of producing counterfeit coin has also increased, and the new coins, owing to the labor involved, would be just as difficult to counterfeit at a profit as the prewar coins.”

Source: The Literary Digest for March 5, 1921