DON'T believe those scare stories about an atomic bomb tearing a crater clear across Manhattan or the Loop. No enemy with enough sense to cook up an A-bomb would waste it with a direct hit on a city. That was good enough in Hiroshima's day, but it is considered pretty primitive now.
Sir: On page 122 of the May issue the following item appears: "... Lockyer, accomplishing the first transmutation of metals, obtained calcium from copper." I should be glad to be advised of the publication on which this is based. I am equally certain that the statement is erroneous and that Lockyer did not accomplish this feat, which has not yet been accomplished.
Here, as a fluid baked onto glass insulators, it breaks water into beads, preventing the formation of a film that would conduct electricity. Silicone compounds are made of ingredients similar to sand and natural gas. Although not new, they have only recently been put to work making rubber stand greater heat, giving more life to petroleum greases at extreme temperatures, floating trout and bass flies high on the water so as to fool the smartest fish.
Our Big Ditch is a dangerous bottleneck in a nervous world; here are three proposed ways to make it safe and efficient•
They Have to Fit
The Ditch's Bottleneck
Going Gets Easier
Two Schemes Proposed
Bombs Get Consideration
A Second Canal
Abandoned in 1942
Anchorage for Pacific End
Still a Three-Way Choice
Stephen L. Freeland
THE Panama Canal is the most dangerous important waterway in the world today, averaging 50 accidents annually for 20 years —an accident a year for every mile of its length. This record in itself is bad enough to justify doing something about the 40-year-old Ditch.
THE new edition of the AAF's jet-propelled Shooting Star, the P-80B, is a faster, tougher, and more formidable fighter. Its six guns, mounted in the nose, capable of firing 1,200 rounds a minute, have proved their accuracy at high speeds. Water injection has been adapted to the J-33 turbo-jet engine to increase power for take-off and climb.
Neptune, now being built for the Navy to outdo Nazis' lumbering weapon, is designed to reach 237-mile altitude.
SEVEN months from now, the U. S. Navy will have a rocket so much better designed than the V-2 that it will be able to soar more than twice as high. It will be slimmer than the sleekest fighter plane's fuselage. It will be able to take off from a battleship.
A HELICOPTER enthusiast recently wrote a book, which he entitled "Anything a Horse Can Do." That may be stretching it a bit, but the "windmill" planes have shown themselves workhorses of the air in many fields. Aside from their dramatic rescue work, helicopters have proved successful in delivering mail and packages, making aerial surveys, laying pipe lines, and have even made a bid in the weight-lifting field.
FOR high altitude bail-out, the Irvin Automatic Opener can be set to open a parachute automatically at a height where air is dense enough to breathe. Low-altitude jumper presets timer, which delays opening until he has decelerated to a speed at which he can withstand opening shock.
Through ingenious studies of how normal limbs function, engineers are helping amputees.
Vacuum Principle Revived
Muscular Electricity Tested
ONE spring day late in the war Howard D. Eberhart, civil engineering professor from the University of California, was testing the runways of the Army's Hamilton Field, using a big trailer to find out if the surface could support heavily loaded B-29s.
If willingness to expend money, men and materials can do it, U.S.S.R. will become the world's No. 1 air power.
the Editors of Popular Science
THE Union of Socialist Soviet Republics proposes to become the world's greatest air power. Russian determination to be first, her increasing expenditures on research, her growing skills, her vast potential of men and materials make her today second only to the United States.
Caltech is exploding myths of garden and farm by investigating effects of sunlight, warmth and moisture.
Tomato-feeding tests show that sugar enters the plant through its leaves.
Tomato plants quit work at 2 p.m., but they grow on sugar during night.
HOW do plants grow? They do not have circulatory or digestive systems that can be studied like those of animals. But, by subjecting them to diverse conditions in a weather factory at California Institute of Technology, plant physiologists are finding out—and exploding many of the green-thumbed gardeners' pet ideas.
WITH a top speed of 170 m.p.h., the Navy's Fairchild XNQ-1 primary trainer has the latest safety devices, such as a bubble canopy for unobstructed view. It is an allmetal, two-place, low-wing monoplane with a 320-hp. Lycoming engine, controllablepitch propeller, and retractable landing gear. The plane won a design competition.
Brookhaven Laboratory is GHQ for reversing what happens when an atomic bomb explodes.
CAN electrical energy be turned into real matter that will continue to exist? What are the forces, stronger than electrical and gravitational forces, that hold the nuclei of atoms together? Related to these questions are many more: Can electricity be drawn directly from atomic piles, or can piles be used only as heat sources?
HARMONICAS, like many another product, have taken their place on U. S. assembly lines. Largely imported before the war, the ubiquitous and versatile instruments, more familiarly known as mouth organs, will be mostly American-made from now on.
THE medals that commemorate the heroic achievements of aviation's pioneers are, in themselves, a history of mankind's triumphs in the air. Here are seven such flight medals that have been donated to the collection of the Institute of the Aeronautical Sciences.
THE Consolidated Vultee XB-46, called the fastest of its type ever made in the U. S., is the second four-jet medium bomber built for the AAF. It resembles the North American XB-45, but is bigger: 105 feet nine inches long; wing span, 113 feet. THREE twin-engine Northrop N9Ms are being used by the AAF to train pilots for the big four-engine XB-35 and its eight-jet-engine counterpart, the YB-49.
THIS whirling dervish is a giant industrial pump that carries its own power supply and is constructed to function efficiently even when completely submerged. Designed to pump both liquids and gases, its built-in, oil-sealed electric motor makes a long drive shaft unnecessary.
Everybody has hit own pet idea of some gadget he would like to see in general use. What is YOURS? Popular Science Monthly will pay five dollars for every such suggestion that its editors decido to publish. Suggestions cannot be acknowledged or returned.
THESE shining litt1e rainbows are clues. Each is the spectrum of a star—its signature in light. From them, astronomers hope to wrest the secrets of the Milky Way. For the Milky Way is no haphazard streak of stars, but the island universe—super-galaxy—of which our sun is a minor member.
A "SANDWICH" bed for severe fracture cases, who have to be turned over several times a day, has simplified what used to be a difficult and painful process. The bed has a mattress that rotates within a metal frame. When a patient lying on his back needs to be turned over, a second mattress is placed on top of him and fastened by wing nuts at the ends of the frame. Then the bed is turned over and the uppermost mattress is removed, leaving the patient lying on his stomach.
RESILIENT synthetic washers that can be changed without turning off the water are said to make a British-designed faucet drip-proof. There are two washers instead of the one used in conventional types, and sealing is effected by water pressure.
THE first of two midget wind tunnels being built at the University of California has a test chamber only one inch wide and ⅜ inch high, but it will simulate conditions up to 70,000 feet and velocities up to three times that of sound. Shown above during assembly, the tunnel is so small that only bits of flat metal and wire can be used in tests.
THANKS to a monorail, the AAF can now parachute two howitzers in the time one used to require. The rail runs along the plane's cabin roof; the guns or other loads are hitched to it. At the push of a button, the floor door opens, and the load is automatically carried to it and dropped through.
HERE is the inside of the Pratt & Whitney Wasp Major, world's most powerful radial, air-cooled, reciprocating aircraft engine. With the rapid advance of turbine power, this may represent one of the last of the mammoth but compact piston-engine types that began gaining favor with the armed services and air lines two decades ago.
THE world's largest aerial camera is giving the Army Air Forces a new kind of bird's-eye view—the kind a bird might get with a telescope. Known as the K-30, the camera is a 575-pound giant with an f/10 lens of 100-inch focal length, designed to give 2½ times more photographic detail from an altitude of 50,000 feet than the largest standard camera now used.
Antiqued Candle Box. Gay designs are painted against a natural pine background, and then antiqued with a thin lacquer glaze to make this box an attractive period piece as well as a convenient place to store candles. Its old-fashioned charm will make it a welcome addition to cabins or cottages where candlelight supplies all or part of the illumination.
IT TOOK a war for the aircraft makers to match the auto industry's assemblyline technique, but now peacetime transports are rolling off. The Convair-240, a new 300-m.p.h., twin-engine transport, is constructed of parts so standardized and interchangeable that a dozen planes could be taken apart, scrambled, and reassembled without a single misfit.
THE bathtub battle fleet has a colorful new recruit—a plastic "rocket" submarine that performs a series of gliding dives onpill-power. The manufacturer, Payne Products, Inc., of Midland, Mich., supplies effervescent tablets designed to propel the craft for six or seven minutes.
IF YOU wanted to buy a washing machine last year, a clerk put your name on a waiting list; if you were among the 2,023981 lucky ones, you took the first make he offered you. This year, you may find yourself in a quandary, forced to choose which of several new washers you want.
ALTERNATING current, the kind you probably use at home, is going aloft. Experts have found that AC generators give 50 percent more power per pound of weight than comparable DC units. Trouble-free operation is another advantage; with AC, induction motors can be used, dispensing with commutator brushes that wear out rapidly at high altitudes.
RADIOACTIVE atoms have turned detective on the track of a killer. A chemical named Inba destroys plants when placed on the leaves. To find out how it slays, radioactive iodine is added to the poison before application. A Geiger counter then traces the course of the deadly compound through leaves and stems.
BOOSTED into the air by four rockets, a Navy KUW-1 buzz bomb roars aloft over the Air Missile Test Center at Point Mogu, Calif. Rockets fall free after two seconds, but the Loon can go on for 150 miles under its own power at speeds above 425 m.p.h.
BRITAIN'S first radio-controlled rocket, developed by the Fairey Aviation Co., has successfully completed its flight trials. Shown being adjusted during a London exhibition, the 7½-foot missile has four main rocket cells, can top 500 m.p.h.
SPEWING flame from its exhaust, a ramjet goes through its paces in a night test at the Esso Laboratories, Linden, N. J. Only six inches in diameter, the jet rivals the heat of 300 home oil burners and can travel at nearly twice the speed of sound.
Massive walls shatter like egg shells when this new concrete-breaker goes to work, as shown during a demonstration in wrecking operations in war-devastated areas of Greenwich, England. The American-built machine, a one-man mobile unit, has a powerful hammer driven by compressed air.
This mobile stone-eating plant chews an 88-ton mouthful in one hour and spits it out in two different sizes. A variable-mesh, doublescreen sifter in the main unit, diagramed below, receives broken rock from a primary crusher, separates the coarse from the fine, and gives large fragments a second crushing.
Portable as a suitcase, they feed oxygen into a maze of tubes and valves to do the work of the human lungs.
In simulated emergency, experts show use of E & J Resuscitator on "nonbreathing" victims. IN YOUR pocket, or on your wrist, is a marvelous little machine that splits time into handy pieces. Your automobile is a whole collection of machines that measure air and fuel, make electricity, pump water, set off explosions, transmit power around comers, and count miles, amperes, degrees of heat and pounds of pressure.
Faulty wheel alignment, often the cause of steering difficulties and rapid tire wear, can be easily detected by the Visualiner, an outgrowth of wartime light-beam gauges. When a car is driven onto the checking ramp, light beams projected on a chart clearly indicate the alignment of the wheels.
To get more power from an oil-burning gas turbine designed for possible use in locomotives, Westinghouse has devised a new nozzle that blasts heavy oil into particles only 4/10,000 inch in diameter. The nozzle, shown below (right) in a comparative test, causes six fine streams of air to collide with incoming fuel.
Checking dimensions to within 2/10,000 inch by the shadows they cast, the new Visi-Limit electronic micrometer can speed the production of wire, tubing and similar materials. A scanning disk sends a light beam to three apertures in turn—maximum, minimum and test—and a photocell picks up the flashes and transmits them to a cathode screen.
ALINE of 36 of the world's brightest lights, equal to more than 1,800,000,000 60-watt bulbs, will enable pilots to make visual landings despite the thickest fog. Each of 3,300,000,000 peak candle power, these krypton lights are combined with neon blaze units to throw up lightninglike flashes.
COLOR television that can be projected on a large screen is the latest achievement of RCA engineers. At a demonstration in a large auditorium, color images were received and shown on a 7½by 10-foot screen. The new receiver-projector utilizes the all-electronic system of color transmission (PSM, Feb.
JIGGER SAVES LIQUOR. Designed to rest across the top of the glass, this 1½-oz. clear plastic jigger lessens the possibility that any liquor will be wasted by accidental spilling for, when full, it can be emptied directly into the glass below.
HAM CARR braked his old red sedan to a smooth stop on the. Model Garage's shop floor and stepped out nimbly. "Hi, there, my friend," he hailed Gus Wilson. "Got time to give this old bus the once-over?" "Sorry, Ham," Gus said, shaking his head. "Not today.
COMBINING the functions of both spring and shock absorber, a revolutionary new hydraulic spring developed in England during the war provides riding comfort through actual compression of a liquid. Produced originally for aircraft undercarriages, it now is being developed by Dowty Equipment, Ltd.
CONVERTING your car so that it will serve as a bed on vacation trips isn't a difficult job, and it will free you of dependence on tourist courts and hotels. Most coaches and sedans as well as many coupes can be modified simply by removing the back seat and adding a mattress platform.
Replacement Front-Seat Unit Folds Back into Car Bed
IN THE commercial field, the problem of putting a bed in a car is solved by a front-seat unit that replaces the original front seat and can be installed in most cars in less than an hour. Its back folds down level with the cushions in the front and rear seats to make a comfortable bed that is long enough for most sleepers even in a short club coupe.
LIGHT UNDER THE HOOD. An engine-compartment light recently placed on the market by the Ford Motor Company lights up automatically when the hood is raised. Quickly installed with self-tapping screws, the light can be connected to the startingrelay switch, voltage regulator, or any hot output wire.
REAR engines and independent suspension of all four wheels are noteworthy mechanical features of two of a half dozen or more midget cars now being developed in the United States for the 1948 market. Several designers also have projected three-wheel vehicles.
Stair elevator on garage-door rails provides safe lift to second floor for invalids and convalescents.
SEMI-INVALIDS and some elderly people find going up and down stairs a task beyond their endurance. For them some sort of elevator arrangement in the average two-story house is a real boon. The problem isn't too difficult for the resourceful handy man to solve, provided the flight is straight, without turns or landings.
Anchor for Small Boat Is Built from Leaf of Old Car Spring
FASTENED to the end of a length of pipe by an expansion bolt, a leaf from an old auto spring provides firm anchorage for a light dinghy or other small boat. A standard pipe tee is screwed to the other end of the shank as a stock through which the rope is passed.
GETTING up to open the door every time your dog or cat scratches to get in or out can become tiresome. Figure 1 shows a swinging door that a dog can open without help. It is a rectangle of plywood fitted into a dog-size opening in the lower panel of the kitchen or other house door.
SHUT IT, RICHARD! It's impossible for anyone to enter or leave our back yard—by the gate—unknown to us, for a buzzer near the kitchen door sounds whenever the gate is open. The diagram shows how it's done. We rigged up the system because forgetful persons were always leaving the gate ajar, letting our dog out and unwanted dogs and other trouble in.
RIVER boats have always been picturesque. This one, a 14" stern-wheeler, is driven by rubber strands and a pair of small bevel gears. It will run at fair speed even against a light current. A paddle-wheel brake locks the wheel until the boat is in the water.
GIVEN a few odd scraps of cabinet wood and a circular saw, you can turn out, in a few hours' spare time, a dozen small craft projects made of strips ½" square. In the photos are two book-end designs and a letter rack; in the drawings are suggestions for a small tray and coasters.
MANY camp and beach cottages have no place for the morning shave except in the kitchen, and this frequently interferes with breakfast preparations. This box for shaving equipment is built around a mirror and a small basin for the shaving water.
Marine Canoe Glue Binds Cloth Patch to Canvas-Covered Boat
RIPS and worn places in the coverings of canvas boats can be repaired with marine canoe glue heated and daubed over the spot, where it will harden quickly. A patch of unbleached muslin or any light fabric, not heavy canvas, is laid over the glue and a hot iron applied. This melts and sweats the glue through, binding the patch and old cover. Such a patch can be smoothed and painted so it will be hardly noticeable.
Box for Candles Is Ornamented with Painted Peasant Designs
STORAGE of candles where they will be accessible but protected is a problem in a cabin or summer cottage. This pine box with a hinged lid keeps them out of reach of small children. It is shown in color on page 116. Construction is very simple, with all joints butted and nailed.
STRETCHED over a length of corrugated cardboard around the body of an electric hand drill, a section of auto or motorcycle inner tube holds drills securely and ready at hand. Fold the piece of tubing back on itself and put the cardboard between.
TWO VERSIONS OF THE TRAILER. Here are two ways readers adapted the trailer published in PSM (Mar. and Apr. '46) to their own needs. John Rzeszutek, of Minneapolis, built the trailer at left, using ⅛" pressed composition wood for the outside, ⅛" mahogany army-glider plywood inside, and ½" insulation board between with ¾" air space on both sides.
THOSE first railroad cars for the future engineer can be built of a few scraps of ⅜" plywood, some pine blocks, dowel ends, and orange-crate wood. Knob-and-socket couplings provide an easy method of making up trains. Two or three evenings in the basement should be sufficient for turning out a locomotive and a half-dozen cars.
IF YOUR basement shop boasts one of those new lock-grip wrenches, try using the tool as a nutcracker the next time you want to remove the nut meats whole. Adjust the wrench jaws just tight enough to break the shells; then no matter how much pressure is put on the handles the jaws won't come so close they will break the meats.
Oiled Bag Keeps Fishing Reel from Rusting in Tackle Box
R. A. JENKINS
SOFT leather or chamois cut in a circle will make a good protective bag for a fishing reel. Stretch out the material on a bench or a wide board, tack it down tightly, and trace a 12" circle on it from a cardboard pattern. After cutting out the piece with shears, punch holes about 1" apart near the edge.
CLAMPED to a stud at the garage door, the trigger pull of a shotgun, rifle, revolver, or pistol can be tested accurately. Tie a 1-qt. or ½-gal. bottle to the trigger by a long cord so it is suspended about 6" above the floor. Then slowly fill the bottle with water from a pitcher, stopping as soon as the weight pulls the trigger and the firing pin clicks.
A SHORT piece of heavy strap iron and a stiff compression spring form the working parts of a reliable catch for a small garden gate. In the end of a 4" by 4" block, bore a hole that is slightly larger than the spring but about 1" shorter than the spring length, and chamfer one edge away from the hole.
BURNED-OUT miniature flash bulbs can be made into good fishing bobbers by splitting the solder on the end contact with a knife, inserting the line, and closing the solder on it with pliers. The bulbs will not become waterlogged and can be used for a long time.
MODERN in its conception, materials, and convenience, this glass-topped desk is of plywood construction. It has a shelf for magazines and reference books, ample drawer space, and a special drawer serving as both support and cover for a portable typewriter.
SOME of those mysterious little gadgets that made certain war equipment seem almost like magic are finding their way to the sales counters as surplus goods. One of them is the selsyn, that onetime highly secret device used in antiaircraft weapons, bomb sights, and radar.
D. C. MOTOR WEIGHS 2 OZ. Here is a tiny power plant that will run at 2,000 to 3,000 r.p.m. on one dry cell for operating models, toys, tiny fans, and the like. It is encased in a plastic housing 1" by 1⅜" by 1 15/32". Miniature Electric Motors, Inc., of New York, is the maker.
Miniature Electric Motors, Inc.
MODEL SAILING YACHT
MODEL SAILING YACHT. This 28" long yacht with a 5" beam is designed after Atlantic Class racing sloops. It carries 390 sq. in. of balloon-cloth sail rigged on a 36" mast and 18" boom. The hull is molded from plastic in one piece and weighted with a zinc keel. A special steering device operates the tiller in conjunction with the mainsail, easing the boat into the wind on strong puffs and keeping it under control. Noma Electric Corporation, of New York, is the distributor. The boat is made to sell for about $30. Total weight is 3 lb.
Miniature Electric Motors, Inc.
SYNCHRONIZED PUFFING. Smoke from the Lionel locomotives is now synchronized with the action of the driving rods and comes out in puffs. An electric bulb in the smokestack melts a smoke-making chemical placed on it and also illuminates the outpouring smoke so it's sure to be seen.
Miniature Electric Motors, Inc.
ADJUSTABLE-WEIGHT GOLF CLUBS
ADJUSTABLE-WEIGHT GOLF CLUBS. A small threaded plug in the sole of each of four matching alumnium-head "woods" provides a means of adding or taking out weights. The plug can be unscrewed with a coin. Reynolds Metal Company, of Louisville, Ky., developed the head.
ACCOMMODATING six to eight persons for dinner, this table nevertheless folds so that it can be placed against a wall, where it projects no more than 2'. Its leaf may be folded over completely or supported vertically against the wall in the style of a console table in a living room or an entrance hall.
COLLETS MADE OF BRASS. Although not intended to replace more expensive hardened steel collets, new brass collets announced by the South Bend Lathe Works are manufactured to the same tolerances and their lower cost makes them especially suitable for odd sizes needed only occasionally.
Wheeled Carrier Saves Back Strain in Toting Heavy Outboards
FOR the boat owner who must lug an outboard motor some distance from his car or camp to the shore, a two-wheeled carrier fills a real need. It will also hold the motor upright in storage. Dimensions shown are for moto♦rs of 3 to 5 hp.; if yours is a larger motor, increase the size and "beef up" the construction.
Rubber Handle on Rope Starts Outboard Motor with Safety
A NONSLIPPING handle for the starter rope of an outboard motor can be made from a 4" length of rubber garden hose. If the rope should get caught in the flywheel, the rubber handle won't damage the motor or injure your knuckles as might be the case with a regulation wooden handle.
Absorbent Pad Helps Keep Rain from Entering Sail Cover
J. A. EMMETT
WRAPPED around the mast under the collar of a sail cover, a pad of soft, absorbent cloth such as unbleached muslin or an old Turkish towel will keep rain water running down the mast from getting under the sail cover. Put three or four turns of the cloth around the mast, arranging them partly over the laced main section of the sail cover, and then lash the cover collar over the pad in the usual manner.
THOSE who take their boating alone can get a lot of fun out of a catamaran-scull. With its single pair of oars, the twin-hulled craft can be rowed at better than 10 knots, and if the exertion is tiring, or you just like lolling in the sun and acquiring a tan, the seat may be rolled forward to serve as a pillow.
WARPLANE wing tanks, which can be picked up as war surplus for about $5, make excellent back-yard wading pools. The pool shown was cut from a wing tank made for a B-17 bomber. It was laminated neoprene and cloth and required a couple of hours of cutting time, but it was so stiff that no frame was needed for rigidity.
SPINNER SPEEDS CHUCKING. With a spinner crank fitted to your lathe-chuck key, you can turn the chuck jaws to position much more quickly. It's particularly useful in reversing the jaws of a four-jaw or independent chuck. Turn the two parts of the handle from cold-rolled stock.
Abrasives held on a paper, cloth, or combination backing with glue are referred to as "coated abrasives." Three natural abrasives, flint, emery, and garnet, are employed, and two electric-furnace abrasives, aluminum oxide and silicon carbide.
AT ONCE the most fascinating and the most difficult part of this engine to build, the reverse gear is derived from Stephenson's famous link motion. The valve rod, which moves the slide valve over the ports, is not connected directly to an eccentric at all, but to a small block that slides in a slotted quadrant or link.
BECAUSE of the high price and scarcity of suitable lumber, you may find it better to build a shop workbench from scrap iron. Metal for this one, made for a 9" lathe, cost $2 at a junkyard. The only wood used was the 2" pine top ($3.50) and the 1" pine shelf ($1).
BECAUSE of reduced friction, a ball thrust bearing will greatly increase the grip of a vise. But even when the jaws are under maximum pressure, a slight pull on the screw handle will release them, enabling you to work with greater speed and ease.
Shadowgraphs Make It Easier to Identify or Duplicate a Key
COMPLETE records of your keys in shadow-graph form may come in handy in two ways. If you want to identify a key from a miscellaneous batch, match it against the graph and you have the answer. If you need a duplicate, the information is at hand. Arrange your keys on a sheet of blueprint or photographic paper in subdued light, lay strips of cardboard crosswise to leave white areas for labelling, expose by turning on a white light about 60" above the paper, and process as directed.
Adjustable Guide Helps Grind Perfect Edge on Cutting Tools
GUY H. LEARNED
BUILT around a door hinge, this simple guide makes it an easy matter to grind a straight cutting edge on a plane blade, chisel, or similar tool. Accurate transverse movement of the blade during grinding is assured by a Ushaped channel base shifted back and forth on a guiding strip. This is clamped to the top of the workbench parallel to the grinding-wheel shaft. A shim placed in the hinge as at right above adjusts the blade at any desired angle.
A BOTTLE of ink installed under a drawing board in this manner is out of the way and safe from spilling. Thrust the neck up through a hole, and support the bottle with a stiff flat spring attached under the board with one screw.
Off-Whites: For warmth, add a trace of Indian red or Venetian red. To avoid stark white on ceilings or woodwork, add a trace of raw sienna, or a trace of raw umber and lampblack. For a cool, faint green cast, add chrome green. Ivory: Tint with raw sienna and chrome yellow light in varying proportions, with traces of Venetian red and lampblack permissible for still further variety.
OFTEN it is difficult to maintain photographic solutions at the proper temperature, and yet the right temperature is important for good print quality, particularly in home-processed color work. This pencil-type immersion heater will warm a solution, either in a tank or bottle, at the rate of one degree per minute per quart.
NEW GRAFLEX CAMERAS. A completely redesigned Speed Graphic and a new Crown Graphic have been announced. Each is being made in the three popular film sizes —2¼" by 3¼", 3¼" by 4¼", and 4" by 5"— and both are grouped in what is to be known as the Pacemaker series.
PORTABILITY is a feature seldom associated with an enlarger, but that is the biggest asset of this one. Designed particularly for the kitchen-table darkroom, it can be quickly assembled and put into use anywhere—clamped to a door, the back of a chair, or a window sash.
Red Filter Converts Flashlight for Safe Use in Darkroom
R. F. DONAVAN
CUT round and fitted inside the lens, a red photo filter will convert a flashlight to many safe uses in the darkroom. Such a safelight will be a help in reading instructions and box labels and in hunting things dropped under the sink or tables. If the disk is cut from a square photographic filter, the protective tissue in which the gelatine is wrapped can be cut along with it and left in place when the disk is inserted. The two layers of tissue will help to cut down the brightness of the flashlight bulb.
HOME-WORKSHOP owners often need to draw their own plans, and a knowledge of simple drafting procedure is helpful. Five errors are shown in the drawings— two in Fig. 2. Can you spot them? 1. A scale is intended only for measuring, never for use as a straightedge.
DRAWING boards, large portfolios, and the like may be too wide to fit comfortably under the arm. Carrying can be simplified if one is slipped over a bent coat hanger that has been fitted with a dowel handle. The extra length will let the board down low enough to go under the armpit.
AIR entering the open ends of interchangeable calking-gun tips when they aren't being used may harden the calking material in them. Once this happens, it may be necessary to boil them in a caustic solution. If you cover the ends of the tips with masking tape, the calking material won't harden.
PORTABILITY in radios suggests the great outdoors, yet few manufactured receivers allow for the different requirements of out-of-door as against indoor listening. With the exception of more expensive models, many commercial portables are either incapable of delivering comfortable outdoor volume or else overload to the point of distortion when they are turned up to an adequate level.
HANDBAG RADIO. Shoulder-strap pocketbooks can please the ear as well as the eye. The complete four-tube superhet handbag shown at right above is made by the ARC Radio Corporation. It weighs less than 5 lb. An identical set is furnished in kit form by the Ubildit Co. Both firms are located in Brooklyn, N. Y.
CRYSTAL DUO-DIODE. A new circuit element developed by Sylvania Electric, known as the 1N35, consists of two germanium crystal diodes mounted in one assembly. The crystals are matched for values of forward and back resistance under typical operating conditions. The most likely application of the new device will be in replacing dual diode tubes, such as the 6H6 and 7A6, in standard AM and FM detector circuits. Two typical wiring diagrams, above, show how the crystals may be employed between the IF and first-audio stages of a standard superheterodyne receiver, or following the discriminator transformer of an FM set. The double-crystal unit is also said to be valuable wherever full-wave rectification, modulation, or demodulation may be required in a balanced circuit.
TELEVISION VIA LIGHT BEAMS
TELEVISION VIA LIGHT BEAMS. High-intensity light beams are being used as carriers for picture and sound signals by the Allen B. Du Mont Laboratories, of Passaic, N. J. For actual broadcasting or in place of coaxial cables for short-range relays, light beams transmit color or black-and-white pictures in light or darkness. A modulated light spot on the screen of a cathode-ray tube at the transmitter is optically focused and beamed at the receiver, which may be several miles away. It is there focused on a photoelectric cell and converted into electrical energy. Output of a photoelectric multiplier is great enough to modulate a picture tube directly, thus offering the possibility that RF and IF stages may be eliminated. The photo at top shows an experimental receiving setup; above, a pictorialized version of how the system works.
CALIBRATION OSCILLATOR. This compact, small-drain unit is built around a 100-kc. crystal and is said to have usable harmonic check points up to 100 mc. Radio Specialty Mfg. Co., of Portland, Ore., makes the device, which sells for less than $15.
NEON PILOT LIGHT
NEON PILOT LIGHT. Consuming under 1/10 watt and operating at any voltage from 75 to 250, this miniature lamp is housed in a metal shell especially designed for panel mounting. It is a product of Industrial Devices, Inc., of Edgewater, N. J.
With 12 double buckets on a 16" wheel, this homemade impulse-type unit needs only a moderate water flow.
C. D. Bassett
THOUGH one of man's oldest prime movers, a water wheel is still a fascinating piece of machinery. Perhaps this is because it appears comprehensible at a glance (although an efficient wheel is actually a product of subtle and inconspicuous design refinements), and because it seems to be a way of getting power for nothing.
Pusher Block Rides Rip Fence for Sawing Small Pieces Safely
USING any old scrap as a pusher on the circular saw can cause trouble when small blocks or strips are cut. This pusher made of hardwood has a sure-grip handle, straddles the ripping fence, can't slip, and can be used for cuts on either side. A 45-deg. corner on the front of the cheeks holds the work down as it is pushed. Make the gadget by screwing two cheeks to a handle piece a trifle wider than the fence.
FITTED with a handle, a 6" length of broken ¼" bandsaw blade will make a useful keyhole saw. The detachable file handle shown has a thumbscrew that clamps the blade. An ordinary file handle could be used with a screw put through it and a hole punched in the blade to hold it firmly in place while sawing.
Wall Hangers Made from Baling Wire Will Hold Small Tools
ELMER H. BERRY
SHORT lengths of ¾" strap metal of the kind used for baling and reinforcing packing cases can be bent into wall hangers for hammers, files, and the like. Make up several form blocks, spacing the nails according to the diameter of the tool handles; then bend the strap on the blocks to make brackets with curled ends.
ULTRAVIOLET radiation that makes the figures on even an old luminous clock dial stand out clearly in the dark can be obtained from a tiny argon bulb. The purplish-blue ray is hardly visible. A ¼-watt argon lamp with a candelabra base can be obtained at radio supply stores; type AR-3 can be plugged directly into a household A.C. outlet.
You can wire an automobile dashboard clock to run on 115-volt A.C. or D.C. as a handsome illuminated-dial house clock. Most car clocks are designed to operate on 6 volts, but since current flows only momentarily on the winding cycle, they can be connected to house current if a 25-ohm resistor is put in the circuit.
AMATEUR photographers and modelmakers find many uses for razor blades, but unguarded edges are a menace to careless fingers. A few minutes spent making this combination guard and holder for single-edge blades will be well spent. With it, a blade can be carried in the pocket.
Simple surgery in time may preserve an asset to your property that would take years to replace.
IT TAKES years to grow a tree and only a season of neglect to destroy one. With the best intentions, owners have done more to hasten the death of their trees by ignorant trimming and improper treatment than disease could do in a score of years. But there is no reason why an amateur, once he understands the problems and provided he acts in time, cannot arrest ordinary decay.
Turned Candlestick Is Made Without Resort to Lathe
R. J. DECRISTOFORO
EMBODYING the simplicity of a Colonial period turning, this candlestick will be a decorative centerpiece for a kitchen or dinette table. It is made from two lengths of dowel of different diameters and two turned holders that can be salvaged from the legs of a discarded chair.
Tethered Power Mower Steers Itself While Cutting Your Lawn
FORRIS B. CHICK
WEARY trudging behind a power mower can be eliminated if your lawn is fairly level and unobstructed by rocks or trees. Running at the end of a 75' clothesline tether, the mower moves in a circular track of ever-decreasing diameter as the line winds itself up on a center post.
ENERGY IN STEP. No matter how weak the force applied to an object, if it is repeated at intervals in step with the object's own rhythm of motion, it will bring about some amazing results. The phenomenon is called resonance. Familiar examples are a child's swing and notes on a piano that cause bric-a-brac to rattle.
TRACTOR PRESS BALES HAY. This press, made by John Deere, of Moline, Ill., picks up hay from the windrows and bales it automatically as a one-man job. A minimum of wire is used in the baling, and there are no short ends to fall to the ground and find their way into future bales.
DRESSED up and glamorized, the five-room bungalow illustrated by the model above is designed to cost only . $4,000 to $6,000. Developed by the Great Lakes Steel Corp., which plans to produce basic units that can be completed by local contractors, its Quonsetlike arch-rib, Stran-Steel construction lowers cost and speeds assembly.
IT TAKES less than a minute for this new wood-gluing press to cement boards together so tightly that no tongue-and-groove joint is required. Developed by the Raytheon Manufacturing Co., the press holds the pieces in a high-frequency electric field between two plates, while the heat thus generated sets the glue in 30 to 50 seconds.
To WATCH the flight of long-range missiles, engineers of the Army Ballistic Research Laboratories have developed a turret-mounted telescope unit installed on a mobile gun carriage. Nicknamed "Little Bright Eyes," the unit has two 4½-inch telescopes: one visual; the other photographic, with a 35-mm.
THE high-grade steel, cadmium-plated pincers and pliers pictured above were originally designed for fishermen, but have been adopted by gardeners for pruning shrubs and vines. The self-opening tools can also be used for mechanical jobs.
A PROPELLERLESS boat, powered by a high-velocity water jet and capable of maneuvers not possible in conventional craft, is a new experiment of the Continental Motors Corp. Designed to turn in its own length, move sideways and astern, and operate in shallow and weed-infested waters, its method of propulsion is known as "hydropulsion."
A WHISK-BROOM travel brush, mounted at the end of a plastic combination handle and case, folds into the case when not in use and can be quickly opened when needed. The Kippy-Kit Company, of Circleville, Ohio, manufactures it.
FOR heavy-duty work at home or in a shop, this disk sander and polishing head combination accommodates a variety of accessories. Made by the Lake Manufacturing & Engineering Co., of Syracuse, N. Y., the device can be driven from below or behind by a ½-inch V-belt.
TEN times brighter than the ordinary 20-watt airplane reading lamp, a new type 2⅝ inches long (inset), formerly used in gunsights, has been announced by General Electric's Lamp Dept., of Cleveland, Ohio. The lamp is recessed into a wall or ceiling to avoid glare.
A SMALL, two-way micrometer-feed sliding table for light milling in the drill press, as well as for precision hole location, is manufactured by Leo G. Brown Engineering Co., of Los Angeles. The table, easily mounted on a drill press, is 7½ inches square and is fitted for one-inch T-bolt heads.
A WRIST watch that tells time in the raised characters of Braille is made by Longines-Wittnauer. To learn what time it is, the wearer lifts a spring cover that allows him to touch the hands and the dots on the dial. When the cover is released it snaps shut automatically, thus protecting the face of the watch.
THERE is no accidental dislodging of a drain plug when the Sur-Seal rubber sink stopper is used. Featured by Los Angeles Standard Rubber, Inc., its handle sets flush with the sealing rim that is level with the drain edge. The stopper can be removed by grasping the handle and exerting slight pressure to break the suction seal.
THE last of five 75,000-kilowatt generators for the Shasta Dam hydroelectric plant in the Sacramento River Valley is shown under construction at the General Electric works at Schenectady, N. Y. When installed, the five generators will produce enough electricity to light more than 10,000,000 household lamps.
DESIGNED to seal 35-mm. doubleor single-frame transparencies in only six seconds, the Thermo-Sealer, a product of the Albert Specialty Co., of Chicago, protects the slides with hermetically sealed covers of glass and plastic. Operating on electricity, it automatically aligns the glass plates and maintains correct pressure and heat.
AN OUTBOARD motor equipped with a device that automatically disengages the propeller when an obstruction is encountered is produced by the Metal Products Corp., of Milwaukee. Smaller and lighter than prewar models of similar horsepower, it also features fingertip controls, dual carburetion, and (arrow) a tilt-up securing lock.
THE Bord-Pri, a new tool for the reclamation of old lumber in razing jobs, is designed to facilitate the removal of sheathing, siding, flooring and other woodwork. Manufactured by the Maco Corp., of Huntington, Ind., the tool exerts an equal distribution of pressure against the entire end of the board to be removed, thereby minimizing splits and cracks.
AS a nation we are blessed with the fortunate combination of natural resources and the requisite technical skills to use them. This combination exists in few other countries. We attempt to help less fortunate nations through the large-scale export of goods, but I am convinced that to provide permanent aid we must add technological skill and knowledge to our material exports.