This section is from the book "Facts Worth Knowing", by Robert Kemp Philip. Also available from Amazon: Inquire Within for Anything You Want to Know.
If your hat is wet, shake it out as much as possible;then brush it with a soft brush as smooth as you can, or with a clean linen cloth or handkerchief; wipe it very carefully, keep the beaver flat and smooth, in the same direction as it was first placed; then, with a small cane, beat the nap gently up, and hang it up to dry in a cool place. When it is dry, lay it on a table, and brush it round several times with a soft brush in the proper direction; and you will find your hat not the least injured by the rain. If the gloss is not quite so high as you wish, take a flat iron, moderately heated, and pass the same two or three times gently over the hat; brush it afterwards and it will become nearly as handsome as when sent home from the maker.- To Scour a Hat when the Nap is Clotted, and to lake Salt Water out. - Get a hard brash, a basin of hot water (boiling), and some yellow soap; rub a little of the soap lightly on the brush and dip it into the water: brush the hat round with the nap. If you find the nap clotted, do not scrape it with your fingers, as that tears it off, but brush it until it is smooth, and the soap is thoroughly out; then take a piece of wood, or the back of a knife, and scrape it well round; you will find all the dirt come out;then beat it gently with a cane.
 
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