• Quick-acting hydraulic or electric brakes
• Channel steel underframes
• Rugged bodies of oak, elm and airplane spruce
• Steel-clad plywood walls
• Spun glass or similar insulation
• Ball-and-socket couplers that practically eliminate the possibility of the trailer breaking away from the tow car
• Drop-type windows that disappear into the walls instead of swinging outward at eye level to create a night hazard
• Cookstoves with steel safety shields and asbestos wings for protection against fire and hot grease
• Electric refrigerators that freeze ice cubes and retain their low food-preserving temperatures for fourteen to eighteen hours between stops
• Steel rub rails around the trailer at the lower edge of the body to afford protection from contact with trees
• Safe space and water heaters
• Electric lights
• Disappearing wash basins
• Soft, folding beds
• Screw-type ventilators operated from inside the trailer
• Screened and storm windows... and even collapsible rubber bathtubs

The trailer on which the tire blew out at seventy weighed only 1,100 pounds. Years of experimental building showed engineers that lightweight construction is not only the most economical but also the safest. Most motorists have only to close their eyes to picture yesterday's box-on-wheels swaying dizzily down the road behind the tow car.

Engineers for the Covered Wagon company, a pioneer in this $25,000,000 industry, point out that a trailer acts like a whip lash in going around curves because centrifugal force pushes it around like a boy playing crack-the-whip. In negotiating a curve the trailer tends to pull sideways and to slew the rear end of the tow ear toward the outside of the curve. So today's rolling home, combining light weight with equal strength, is built a little wider than the automobile, resulting in smooth travel at speeds up to, and sometimes exceeding, a mile a minute. As every motorist knows, light loads are also more easily controlled. Some factories refuse to build trailers heavier than 3,500 pounds and the small-size trailer rarely weighs more than 1,500 pounds.

The trailer on which the tire blew out at seventy weighed only 1,100 pounds. Years of experimental building showed engineers that lightweight construction is not only the most economical but also the safest. Most motorists have only to close their eyes to picture yesterday's box-on-wheels swaying dizzily down the road behind the tow car

Engineers for the Covered Wagon company, a pioneer in this $25,000,000 industry, point out that a trailer acts like a whip lash in going around curves because centrifugal force pushes it around like a boy playing crack-the-whip. In negotiating a curve the trailer tends to pull sideways and to slew the rear end of the tow ear toward the outside of the curve. So today's rolling home, combining light weight with equal strength, is built a little wider than the automobile, resulting in smooth travel at speeds up to, and sometimes exceeding, a mile a minute. As every motorist knows, light loads are also more easily controlled. Some factories refuse to build trailers heavier than 3,500 pounds and the small-size trailer rarely weighs more than 1,500 pounds.

Manufacturers urge owners to try to equalize the load in packing the trailer. Too much load aft will cause the trailer to "fish-tail," which is annoying and sometimes hazardous, particularly at high speeds. A preponderant weight on the right side will tend to run the trailer down off the crown of the road. Where the highway is bordered by soft dirt shoulders, this is dangerous. Still another recommendation is that the owner have his auto headlights readjusted with the trailer attached. Otherwise, with the rear of the car depressed by the additional weight, the beams will be set at too high an angle for safe driving. An external rear-view mirror, mounted on the car door or fender, is essential for the car-and-trailer unit.