In the 1930s the Innerspring mattress becomes widely used. 'Spring that ensures more restful sleep'. In the making of a Vi-Spring overlay mattress, spring follows spring until a 4' 6" 'Vi-Spring' contains no less than 1056 springs. With each little spring adding its quota of comfort the 'Vi-Spring' becomes a thing built for joyous rest, exquisitely soft, luxuriously resilient, a mattress on which you can lie in glorious relaxation, enjoying sound, health-giving sleep. Your night's rest depends so much upon the mattress.