One-armed drivers had better restrict their activities to the sofa or the back seat if the safety of the roads is to be preserved, in the opinion of Dr. Harry R. de Silva. He has recently joined the staff to the University Bureau for Street Traffic Research and will direct a year's study on the cause and cure of accidents from the viewpoint of the individual driver.

"A person who is operating a car cannot do two things at once, especially if one of them requires a great deal of his attention. It is often disastrous to carry on social intercourse in traffic, for as a general rule conversation is distracting, although on a long fatiguing drive some pleasant music can be relaxing. Radio ads have a terrible effect, on me at any rate!"

Aside from these general remarks, Dr. de Silva's most interesting observations were concerned with the system of tests of driving skill which he has invented and developed himself, and which has received a large amount of current publicity.

He has recently moved his testing machines from the Massachusetts State College at Amherst to Harvard; the exact locale of the present establishment is the basement of the Cambridge fire house, between Memorial Hall and the Yard, where a formidable wire netting protects from the prying public a maze of glare vision meters, braking reaction machines, and other complicated mechanisms.

Braking reaction is measured by noting the interval between the flashing of a red light and the moment when the brake pedal in a model car, operated by the subject, is completely pushed down. "Contrary to the popular supposition", stated Dr. de Silva, "the braking time of the average person after taking a drink of gin is faster, not slower, than normally. Of course, the general efficiency of the driver is lowered, and his coordination is not so good, but in this one case the body reaction is speeded up."

At present the testing machines are on exhibition at Hartford; Philadelphia, and New York, where Dr. de Silva is going today to attend a safety conference. But by next week the apparatus will be set up, and any students who wish to find out their efficiency at the wheel will be welcome.