LIGHT, as a healer of ills, has been used by people throughout history. The early Egyptians and Romans took sun baths when they were suffering from disease, believing that it was the heat in the sunlight that helped them. Sun baths are still somewhat in vogue, but we know now that their stimulating effect is due to the chemical action of sunlight, not to its heat.
ALTHOUGH we have grown used to machines on the farm, there is one agricultural operation that has for years baffled the inventors skill—that is, the picking of cotton. Even in this day of machineray cotton the world over is generally harvested by hand.
ACCORDING to early calculations, the present orbit of the Pons-Winnecke comet was expected to collide with the earth in June. On april 10 Professor Barnard, of the Yerkes Observatory, located it, and later calculations indicated that the expected collision would not occur.
WHEN disease has taken firm hold on the breathing apparatus, it becomes necessary to aid nature by carrying germ-destroying agents directly to the seat of the trouble. In normal respiration, air invariably laden with germs and impurities is drawn into the lungs by the expansion of the chest, which causes diminution of the air pressure in the lungs.
THERE has been developed and patented by Guyon F. Greenwood, of Quebec, a metallurgical apparatus for the production of iron that avoids many of the disadvantages of the blast-furnace. The essential features are the reduction of iron oxide by means of carbon with the exclusion of air in an electric resistance furnace and at a temperature and pressure favoring the production of carbon monoxid, the latter being used as fuel in a gas engine generating electric energy utilized in heating the electric furnace.
MOLDS thrive on warm, moist wood. In a dry-kiln molds often obstruct the circulation of air through the pile. The Forest Products Laboratory found that the surest method of stopping this growth is to steam the stock at 170 or 180 degrees for about an hour.
A MECHANICAL hammer has been invented that can deliver as many as four hundred and twenty blows a minute when speeded up. The strength of the blows may be varied by adjusting a spring As this spring is pulled upward the blows become lighter; when the screw is turned down, the blows become heavy.
SOMEBODY has reckoned that if the earth’s population had increased 4½ Per cent every hundred years since the birth of Christ, by now there would not be standing-room left on the globe, including all the islands. Yet England and Wales in ten years increased their population 161 per cent, and the increase in the United States has been much greater.
NINETY million cubic feet of stone sprawled out over thirteen square acres and reaching nearly five hundred feet into the sky, makes up the tomb of the tyrant, Cheops. A hundred thousand naked slaves toiled for twenty years in the blistering Egyptian sun to build this pyramid.
It was at the Hunstanton station of the Royal National Lifeboat Institution in England that the idea of using the caterpillar tractor to launch life-boats was evolved with such success that now twenty English life-boats are being provided with this means of launching.
STANDING on the seashore on a fine day, it is difficult to believe that a great storm is approaching from beyond the horizon: that in a few hours great waves will be racing in with a howling tempest of wind, breaking with almost irresistible force, flinging tons of water on high, and sweeping the shore in swirling masses of foam.
THE inventor of a new electric furnace has employed a principle that makes his device unique. A repelling arc is used. The layman can understand the principle by considering the electric arc light used to illuminate city streets. Here an electric current is caused to flow across an air-gap formed by two carbon electrodes.
IN order to do away with smoke from ships’ funnels, an Italian invented an apparatus consisting of a slightly conical doubled-walled shaft, placed in the lower part of the funnel. The space between the walls is divided into two compartments. Warm water from the condenser is conducted into the lower compartment, while the upper one is supplied with cold water furnished from a force-pump.
THE tiny Eskdale railroad, running between Ravenglass and Boot, in England, is not a toy railroad, though it looks like one. It was originally constructed for mineral traffic, but is now much used by sightseers in the lake district, and from Boot many delightful excursions may be made.
ONE sheet of steel no larger than a large sheet of cardboard, and not much thicker, can be moved about by one man without much trouble. But how about fifty of these stacked together? The old way to unload a freight-ca containing these sheets of steel was to use a truck hauled by a number of men.
DID you know that if a ship’s debts are not paid the ship can be arrested? Even though it is not actually the ship’s fault a writ is nailed to her mast, a watehman is on board, and the ship is not allowed move until her debts are paid. The creditor must however, be sure of his case; if not, the ship’s owner may sue him for delay and loss of use.
THE old saying that music has charms to soothe the savage breast may be true in some cases, but a recent demonstration at the Central Park menagerie in New York city failed to prove its truth in the case of caged animals. When some musicians, playing wind and string instruments, appeared before the cages, the animals sat up and took notice—at first.
SHOWN at the “load-and-look” idea. Bulk merchandise is usually sold by weight, and speeding up the weighing has always been a problem. With the crane scale here shown a manufacturer may load his freight-cars or -trucks and weigh the merchandise at the same time.
WHEN seeds are to be planned in beds or rows, it saves time to use a sowing-machne. The illustration shows a type-that may be used for planting in one row or in several parallel rows. It consists of a container divided into compartments Each compartment has an opening at the bottom, the size of which can be regulated according to the size and quantity of the seeds. The container rests on spiked wheels and is pushed by means of a handle.
RECENTLY an operation was performed on a man whose nose had been so injured that he was unable to breathe properly. First the broken section of bridge bone that caused the obstruction in the nose was removed. The next step was to cut a bit of bone from one of the man’s left ribs, and to insert it in place of the bridge that had been removed.
Discovered: a New Phenomenon of Electrical Attraction
It will lead to interesting industrial developments
How the New Force Is Applied
Only a Small Current Needed
A NEW electrical phenomenon of attraction has been discovered by two young Danish engineers, A. Johnsen and K. Rahbek. It is a discovery that will eventually lead to new commercial and industrial developments, since it has been found possible to apply the phenomenon.
WHEN a barograph is spoken of, most of us think only of a delicate little instrument that is used for recording altitude. A barograph is nothing but a recording barometer. Recent experiments have revealed that it is possible to use the barograph as an aid to commerce in the production of records of every form of travel by land and air, computing the average time consumed in any given journey, and tracing the movements of delicate and costly shipments.
THE naval battle of Jutland was one of the few great events of the war in which the “movie” man did not figure. A moving-picture producer of England decided to re-stage the battle with the use of tiny models. It was a tremendous task, since every detail of the movements of the German and English fleets had to be carried out.
ROY RUSH, of the Ringling Brothers and Barnum & Bailey Circus, can train a dog or a monkey in six weeks. In the “biggest show on earth” the audience sees a fluffy little dog balancing himself upright on a slack-rope. The dog puts his fore feet upon the rope, then mounts it with his hind feet, and for an instant balances himself on all fours.
AUSTRIA is a country of many caves. It has been discovered that in many of the caves among the Salzburg Alps, especially the, Dachstein and Tennen ranges, the floors were piled high with natural fertilizer. The origin of these piles of organic matter is ascribed to the remains of the bones and excrement of prehistoric animals, most of which are covered with deep layers hundreds of years old of bat guanc.
"THIRTY-TWO,” mumbles the tailor as he wraps a measuring-tape around you; then he tackles another spot, and another. No wonder men hate to have their suits made to order. Now, however, with the aid, of a camera a chart, your measurements can be taken at two clicks.
THE issue of many legal cases turns on the authorship of a given sample of typewriting. Now, though by no means a hopeless task, the identification of typewriting affords incomparably greater difficulty than that of handwriting. According to Professor W. Scheffer, a microscopist who acts as legal expert in such cases, the first step is to ascertain the general type of writing—Roman, Gothic, italics, imitation of handwriting, etc.
PHYSICIANS in New York city may now listen to their patients’ hearts beating in San Francisco. The heart produces a delicate sound that may be heard by a person placing his head on the patient’s chest. The vacuum tube that makes possible the long-distance listening just mentioned is a new stethoscope.
It rivals American sweet corn in flavor and grows at the rate of a foot a day
Captain H. P. Sheldon
A GIANT grass four inches thick that grows a foot a day until it is fifty feet high -—such is bamboo. Its sprouts rival our sweet corn in succulency and flavor; its towering stem will furnish timber to make furniture, fans, and fishrods, tent-poles, trellises, and toothpicks; its graceful outlines and green and golden beauty rival that of the white birch.
Two glass plates superposed show what paper has been taken from your desk
What Stones Have Been Shifted in this Wall?
The Telltale White Streaks and Spots
SUPPOSE that a complicated machine is to be drawn—a new type of locomotive. Suppose that the designing engineer modifies the construction from time to time. He changes the position of a connectingrod here at one time, or the position of a lever at another time, dispenses with a gear, inserts a spring where there was none before.
NEW uses for the farm tractor are constantly coming to light. The picture above shows an Iowan farmer pulling up a small tree with his gasoline tractor. When the driving wheels are properly shod to give positive traction, the machine makes short work of hauling the trees up by the roots.
TO resuscitate persons who have been drowned or who have been otherwise asphyxiated, the chest is rhythmically compressed. Sometimes the victim of asphyxiation dies because the would-be life-saver is exhausted and is forced to give up his efforts.
REMINISCENT of Roman conquerors are these shield-shaped paddles. But they are not intended for the gentle art of self-defense; they are meant to increase a swimmer’s speed, in emulation of the webbed foot of the duck. It is very simple to understand that a flat surface, not too heavy, will offer a more effective resistance to water than the hand, and that a person would be propelled through the water with much greater speed by using these paddles.
YEARS ago, wind power was commercially possible. It simply had to be, since there were few other sources of power. Today we get most of our power from coal and a great amount from water. Palestine is not favored with either coal or water power, and Dr. I. M. Mayersohn is now studying the problem of wind power to determine whether or not it will be possible to run industries of Palestine with wind-motors. He has collected interesting data on wind motors in Europe.
HAVE you noticed that the trailer has left the farm and gone to the city? It appears nowadays behind the limousines belonging to the very best families. In shape it resembles an ancient chariot. What is it used for? Carrying trunks, suitcases, and other pieces of luggage.
WHEN you buy a phonograph, the price is governed as much by the case as by the mechanism. As a result, many people buy cheap cabinetless phonographs at first, and then wish later that they had not been so economical. Now they are able to buy empty cabinets into which they can drop their small machines.
"IS the coffee done?” That’s a hard question to answer. Now, however, there is a coffeepot that stops functioning when the coffee is done. The pot is divided into two sections, separated by a metal partition. Throug its center runs a tube,and at the top is a compartment resembling a percolator.
THERE is a ferry-boat on the Thames, England, that has no Charon to guide it from one bank to the other. It was built to enable motorists to get across without taking the usual roundabout trip, and it is operated by the motorist himself. The boat measures fourteen by twenty feet, allowing plenty of room for even very large cars.
FOR butting coal-cars up an incline, a big railroad uses a mechanical billy-goat. The “goat” is attached to a long cable, which is wound upon the drum of a powerful hoist. This hoist does not even groan when it is pulling up a 60,000-pound load.
"A CONTINUOUS highway from the Atlantic to the Pacific, open to lawful traffic of every description”—this was the plan of the originators of the Lincoln Highway. In pursuance of this plan, in seven years’ time $3l,284,520 spent in improving the road.
THE tiny Bewick’s wren who built the nest below chooses to dwell near farmhouses in many parts of America. Sometimes it will build its nest in an old straw hat hung in an out-of-the-way nook, a rusty bucket, or an old shoe,and one nest was seen in a tin can that lay in a barrel of trash in a farmyard.
ONE quarter of all the people in the world live in China. And there is not enough fruit in the country to supply them all. Hence Japan and the United States are both selling fruit there. In the picture below YOU SEE A FRUIT-STORE in Peking. The fruit has been arranged to good efect by the three smiling vendors. Apples, oranges, lemons, and grapes that were grown in the United States are sold there. Until recently the people of the upper classes were the only ones who were able to to buy fruit.
USUALLY it is when a man is in the greatest hurry to shave that the razor-blade is found to be dull. That is the time the little sharpener shown above will come in handy. No leather or rubber belt or wheels are used. The blade is clamped in a little vise and the sharpening substance is moved back and forth over the edges.
AN attachment for an adding-machine has been invented, with the result that the blind can very easily learn the tricks of such a machine. The original design is the invention of a blind man, J. R. Oastler, and all of the necessary details have been worked out under his instruction.
PICTURED above is a garden rultivator that not only cultivates all garden crops, but that also churns, digs potatoes, serves as a cream-separator, mows lawns, pumps water, and runs a grindstone! It weighs two hundred and eighty-five pounds when fully equipped.
ARGENTINE ants are such pests that when they decide to invade a house, two minutes after the table is set, it may look like the one below— completely overrun! In spite of their South American name, these ants are found in the United States— they were introduce years ago on coffee ships landing at New Orleans from Brazil.
You Can Stick Pins in This Self-Healing Rubber Ball
HERE is a ball that is bullet-proof, pin-proof, and dog-proof. It is made of very live rubber with a light coating or skin like that on any other rubber ball, while the interior is made of spongy rubber. A glance at the above picture will convey an idea of what the ball will stand.
“IF you have tears, prepare to shed them now,” says Mary to her doll. Whereupon she squeezes a bulb that is concealed in the doll’s back, and two large tears gush forth from the doll’s eyes. Such is the new crying doll recently invented by George J. Hoefler, of Stapleton, New York.
THIS fountain-pen “winds” up like an eight-day clock. It will draw a line two miles long before its supply of ink becomes exhausted. It requires a lot of writing to make a line a mile in length. The ink is drawn into the pen in a new way—it is pumped in.
WHEN a bud is grafted to a tree, the resulting wound must be bandaged until it heals. But this bandaging process is difficult and slow. Vincent Tollis, of Clifton Springs, New York, has invented a “budding-clasp” that is operated with all the simplicity of a clothespin.
HOSPITAL ships of to-day must wear a red cross not only on the side and stack but on top. This is to guard against attack by hostile aircraft. In the picture below you see the large cross of the U. S. S. Relief, an oil-burning hospital ship. By day its coat of brilliant red paint makes it plainly visible from above, and at night it is constantly illuminated, as are the red crosses on the side of the ship’s hull and smokestack.
SINCE the war the French government has issued almost hysterical appeals to the populace offering prizes for large families. This has had some result, but not nearly enough. Why? Because the question of infant mortality was not taken into consideration, and apparent gains were short lived because nullified by the large death rate among children—from 15 to 20 per cent in children in tneir first year.
MILLIONS of shells of all sizes were left over from the war. An Englishman has invented a small hydraulic jack that can lift ten tons. It is made from a 4.5 high-explosive shell and the ram from an eighteen-pound shrapnel shell. The detachable head of the 4.5 shell is divided into two pieces just a little forward of the shoulders that normally screw on to the body.
EVERYBODY IS familiar with those flat pieces of cardboard or wood that can be transformed so quickly into boxes. Some of the boxes are bound with wire. This wire must be fastened securely together at the ends. While a pair of pincers would serve, the resulting twist is easily undone.
HERE is a headlight that is literally a head light. It is a light that you wear on your head. The wires and battery are concealed bandeau worn around the forehead, and the ands out in front. This lamp was probably invented after the idea of the miner's lamps that has also been adopted by physicians, surgeons, and dentists its especial value to them being that both hands are free.
WITH his old oil lantern, the fireman always took a great chance when he entered a gas-filled room. An explosion might occur. The fireman’s little electric flashlight shown below is perfectly in every way. The switch is conveniently located near the handle.
LIVING in a country of five hundred lakes, Virginia W. Collier thought: “Why can’t I invent a portable dressing cabinet?” Here was a real automobile need. Her first thought in the plan of folding and of carrying the cabinet compactly was suggested by a box-kite From this idea she developed a similar structure that would stand on end, firmly planted by its spiked uprights in the ground, with an X at the top to give it support and maintain its form.
DOES man accomplish much in his three score years and ten? Some interesting calculations have been, made to find out what a man does with his time. Basing these calculations on sixty years (counting out the first ten years of life as the period in which the subject receives more or less help in these duties), somebody with a flair for figures has made the chart below.
SHOULD your hat be made of noninflammable material, you use it to cook your lunch in, says the woman in the picture above. She turned her hat upside down,filled it with water, and placed it over a small alcohol stove. When the water reached the boiling-point, she dropped in two potatoes.
IN a small settlement on Vancouver Island, the natives used to bury their dead in a singular manner. “Bury” is hardly the word, since the corpse was not put below the ground but was elevated high above the ground on or in a column of cedar. Besides the moss-covered figure at the top of the pillar, a corpse may also be found resting inside the door at the back of the carved figure, and there is another corpse in the panel below.
"FOR SALE.” When you hang up this sign in front of your house, the people who pass by are the only ones who will see it. And if your house is on a quiet street the chances for selling it are not good. A Los Angeles man found himself in this predicament—his house was on a hill about three blocks from the main road.
OLD-FASHIONED smoke-houses in which pork was either cured or burned up with the house are being replaced by a less dangerous and more sanitary smokingstove. This stove is made and is mounted on wheels. It has a large oven in which the hams, bacons, and sausages of ten hogs can be cured at one time.
THIS device, a big help to the small farmer, is a weeder that cultivates as it weeds. It is adjustable in width so that it may be used between rows of plants placed any reasonable distance apart. The weeding teeth are attached to two arms which may be adjusted to any angle.
PETROLEUM is not going to last forever. The supply is now getting low. Other substances may be used, but it has not been necessary to develop the other sources while there is plenty of gasoline. Far-sighted investigators have been at work on this proble, for a long time.
REPOPULATING denuded forests is a job that falls to the United States Forest Survey; and it is done in the following manner. The seedlings are kept in a nursery during the first two years of their lives; then they are transplanted to the ground.
SIMPLY unscrew the handle of the cane shown below, take from the hollow interior two sections of rod, attach them to each other and then to the end of the cane, and you have a fishing-rod. On the large handle there is still a smaller handle. By turning the small one you open two doors at either end of the large one and take your tackle and worms from the hollow cases within.
PERSISTENT rumors have been afloat that Thomas Edison invented the typewriter. As a matter of fact, credit for this should go to C. Latham Sholes, who started his experiments on a “writingmachine” in 1867. Nobody is more anxious to have this matter straightened out than Mr. Edison.
THE first electrically propelled trawler has been built. It carries two large and powerful Diesel engines, which are directly connected with two generators. The genarators, in turn, supply current to electric motor, which drives the trawler. This motor is connected with the propeller-shaft, and it maybe controlled from the pilot’s cabin, where the necessary switches are located.
HAIRDRESSING has not escaped the efficiency net, and recently a number of tests were given in a school for hairdressers, the object being to speed up that occupation. The tests proper were preceded by a written test to ascertain the pupil’s mental elasticity aside from her profession.
WE have just come to realize that coal is valuable for no less than seven thousand substances useful to society. Only one tenth of the product is converted into these thousands of invaluable compounds, which means an annual waste to the United States of two billion dollars of coal by-products.
TROLLEY-TRACKS are very much in the way. Hence the trackless trolleycar is now coming into use. The car gets its power from an overhead wire by means of the usual trolley-pole. The motorman must steer the car, as well as control the power and brakes.
With the assistance of the chronometer and sound waves
Can Sound Be Depended Upon?
Enter the Chronometer
P. J. Risdon
ONE of the principal difficulties that confront an aviator is that of ascertaining his position and altitude when flying through or above clouds or in foggy weather. Another is to locate a flying-field and to land there in a fog. Since, in employing aircraft for business and mail-carrying, flying must go on in all weathers, means must be found for doing so in safety.
Guiding Airplanes by Explosions Recorded on a Chart
This system of locating an airplane is based upon the time taken for the sound of an explosion, set off by the pilot of the airplane, to reach the earth and rebound to the airplane. The altimeter now used merely indicates the height of the machine above sea-level.
WHEN you talk, you cause the air between your mouth and the ear of your hearer to pulsate. Like air, water can be made to pulsate. If you strike a bell on the water, the sound will travel much farther than in air. Hence, many ships are equipped with bells, which are sounded under water and which are much more efficient than fog-horns.
There is a machine that does this with perfect accuracy
What Is Electric Induction?
How a Fly Bends a Half-Inch Steel Rod
The Condenser in Action
C. A. Briggs
Raymond F. Yates
THE sun Betelgeuse is about 354,000,000,000,000,000 miles distant from the earth. A distance of one two hundred millionth of an inch has just been measured. Our imagination is helpless when faced with such tremendous figures. In the one case, man’s unit of measurement, the inch, is hopelesly large; in the other case its smallness makes it utterly insignificant.
Measuring a Millionth of an Inch in the Machine-Shop
Above is a practical electrical measuring device for shop use that is sensitive to one one millionth of an inch. It is so designed that it can be manipulated by a workman without any knowledge of electrical or physical laws. A lever system with a ratio of 100 to 1 is used in connection with the measuring condenser, which is shown mounted at the end of the steel bed.
ONCE two teams of horses and at least two men used to be required to level and grade roads. Now we have the oneman machine, which does the job in half the time and never gets tired. Like ail modern devices of this nature, it is, of course, driven by gasoline.
THE square coin is coming into use in Australia. Before long all of the round Australian halfpennies will be called in. There are two good reasons for minting square coins. They pack better when they are boxed, and very little metal is wasted when they are cut out of the sheet.
ELLING O. WEEKS, a professional aviator, worked for five years on his device for automatically keeping the automobile radiator full of water before it was perfected. It consists of two main parts, a tank and a float-controlled valve, connected with piping.
IN these pages of ideas about automobiles and motor-trucks the Popular Science Monthly endeavors to help its readers solve problems of maintenance and repair. But there must be special cases that are not covered, and we invite you to write to the Automobile Editor and let him advise you.
To reduce tire wear, measure the action of your automobile wheels
WHEN automobile wheels are out of proper alinement, the result is excessive tire wear. Most corrective methods, however, have measured the alinement only when the wheel was stationary. This is not sufficient to reduce tire wear, because the tire does not wear when the wheel is stationary, and because the true or running alinement may vary considerably from the stationary alinement.
If you have a motor-truck or automobile problem, let the Automobile Editor solve it
Why Disk Clutches?
Block Engine Castings
Proper Brake Clearances
When Trailers Pay
Cooling the Engine
Q.—What have been the fundamental causes behind the growth in popularity of the wet and dry metal disk clutches in automobiles today as compared with the type used almost exclusively several years ago?— D. F. G., Reading, Pa. A.—The advantages of the multiple dii k type of automobile clutches as compared with the cone design may be briefly summed up as greater ease and smoothness of operation; less liability to get out of order; greater compactness and a reduced spinning tendency due to less inertia of the driven member due to lightness and small diameter.
THE illustration below shows a boiler for generating steam enough to run a small turbine. A number of semicircular partitions or bulkheads are placed along the bottom, dividing it into a number of compartments or cups. With these, the boiler may be tipped at a considerable angle, yet expose a maximum amount of water to the heat.
WITH the coming of warm weather, the proper cooling of drinking-water on farms and in localities where the water supply is held in elevated tanks, becomes an interesting one. an one. After a few hours under the heat of the sun this water becomes tepid and often unpalatable, even after running through underground pipes.
A VEST-POCKET camera of 2¼ in. by 3¼ in. size is one of the greatest companions that one can have. Opportunities present themselves at the most unexpected moments and, when one has a good lens, some remarkable pictures can be procured that are certainly worthy of enlarging.
THE owner of an automobile should not be too vigorous in polishing the nickeled parts of his car, otherwise, after a few months, the brass or steel will show through. In caring for these parts use only the same polish as is used for silver articles and rub only sparingly.
IN order to save time and insure accuracy in measuring the sizes of pipes in dark places, difficult of access, the pipe gage described below was made. It will instantly give the conventional standard sizes of standard wroughtiron pipe from ⅛-in. to 2½-in. inside diameter, these sizes being most commonly used.
AFTER I had broken a number of pocket rules while trying to use the end for turning screws, I made an attachment for my 6-in. scale that is shown in the illustration. The hardened and tempered tool-steel screwdriver point is clamped to the scale by a knurled screw.
ASPRING winder of simple construction and which will wind a spring the length desired is illustrated below. The outside shell is a piece of smoothbore pipe twice as long as the spring is to be and with an inside diameter equal to the outside diameter of the spring. The winding-rod is of solid steel, the diameter of which is the inside diameter of the spring.
THE average housewife does not like to open the door to book-agents, peddlers, or beggars. It is often a great convenience to know who is at the door. By the use of a little mirror arranged at an angle of 45 degrees outside the window, this is made possible in many cases. It all depends where the door is located. If it is at the side of the house, this mirror may be placed outside the kitchen window. Any one at the door will be plainly visible in the mirror, while the person on the inside cannot be seen from outside.
A SIMPLE, safe, and inexpensive toy cannon is made as follows: Plug one end of a length of gas-pipe and screw a spark-plug either through this plug or near it. On top, near the plugged end, screw in a priming-cup similar to those sometimes used on balky gasoline engines.
VERY good results can be obtained with cut films in plate-holders by the following slow developing method. Use a weak bath and hang the film at the side of a glass jar by means of a spring clip, with the gelatin side out, using, say, two films for a jar.
SOMETIMES motor-boat engines and even stationary engines collect sand or sediment in the water jackets through the circulating pump. In time the cooling of the engine is impeded and serious overheating may result. One way to remove any such collected sediment is as follows.
A SCREWDRIVER that was made for the purpose of removing electric contacts from coils and switches under the cowlboard of an automobile is shown in the accompanying illustration. Opposite the screwdriver on the handle is a hexagonal opening for loosening the small terminal nuts.
WHEN meat has to be boiled for a long time, it often happens that the water boils away and the part of the meat touching the pot is scorched. This can be prevented by the use of the shield illustrated here. It is simply a disk of tin or agateware with three or four little feet that raise it about ½ in. from the bottom of the pot.
A DUMB-BELL of variable weight for heavy-weight lifting can be constructed of pipe fittings by any one with a mechanical turn of mind. No dimensions are given, as the length of the handle and size of the bells will vary. The handle is of 1-in. iron piping of the desired length.
SHOWN in the accompanying illustration is a device that is used for holding ¾ by 2½ in. countersunk head-bolts while the thread is being cut in the bolt-cutter. The holder is made of machine steel, casehardened, and is securely clamped in the jaws of the bolt-cutter with the slot in a vertical position, and extending ahead of the jaws.
THE solid end of an old curtain-pole can be made into a toy torpedo with little trouble. The center is bored out and a hook is placed in the forward end as shown. To this hook are fastened several strands of rubber bands similar to those used on model airplanes.
BY soldering a thin piece of an old sawblade to a discarded iron trowel handle, a good pointing trowel may be made as illustrated in the picture. The saw-blade is cut in the desired form with a chisel, and the part to which the handle is to be soldered is first cleaned with sandpaper and then tinned.