Sorry to disappoint but seriously now - it is Beaver Bower, not Blower. See below:
Bowing
"The process of bowing was both a cleaning and fluffing operation. At this stage, the fluff would begin to mat together loosely. Bowing was done by placing the fluff on a hurdle or square table with many evenly spaced parallel slots. The table would be located by a window to provide good lighting. Drafts were avoided to keep the valuable fluff from blowing away during the process. Hatters considered bowing an art and one of the most delicate parts of the process.
The fluff was divided and bowed one half at a time. The Hatter's bow resembled a large violin bow. It hung from the ceiling directly over the hurdle. The bow's one string would be plucked with the thumb or with a wooden bow pin. This caused the string to vibrate over and among the fibers. The wool was fluffed, separated and agitated by this process. Dust and dirt fell through the parallel slots in the hurdle. The wool was spread out much like rolling a pie crust and the fibers continued matting together.
The wool, now called a batt, would be in the shape of a large oval sheet about 4 feet long, 3 feet wide and 6 to 12 inches high. Pressure would be applied with a slotted wooden Hatter's basket and maybe an oil cloth. By this point the fibres were matting together enough to allow handling of the batt. The procedures are then repeated with the other half of the beaver wool producing a second batt".
By the way, the mercury used in the hat-making process made hatters mad - hence the Mad Hatter's tea-party. Much of England's hat trade was centred on Luton and that resulted in the erection of various Lutonatic Asylums in that area.
