CHAPTER I.

HISTORY OF MECHANICAL CLEANING.

PAGE

Early Attempts 3 Limitations of the Carpet Sweeper 4 Compressed Air Cleaners 5 Vacuum Produced by Compressed Air 7 Compressed Air Supplemented by Vacuum 7 Piston Pump the First Satisfactory Vacuum Producer 9 Systems Using Vacuum Only 11 Renovator with Inrush Slot 13 Steam Aspirators Used as Vacuum Producers 14 Piston Pump Used Without Separators 15 First Portable Vacuum Cleaner 15 First Use of Stationary Multi-Stage Turbine Blowers 16 Separators Emptying to Sewer by Air Pressure 18 Machines Using Root Blowers as Vacuum Producers 18