Abstract :
The vertical focusing adjustment for headlamps using two-filament lamps is not only unnecessary but so greatly complicates the correct focusing and aiming of the headlight beam that few persons can make the proper adjustment, asserted A. W. Devine of the Massachusetts Registry of Motor Vehicles, at the summer meeting of the Society of Automotive Engineers at French Lick, Ind., May 1927. He advocated dispensing with the requirement for double focusing in state motor vehicle regulations and declared that improvement in headlighting will be retarded if state laws or regulations require the vertical focusing adjustment in addition to the horizontal adjustment.