48 



Hardwood Record — Veneer & Panel Section 



October lO. 1921 



Beautiful Birch 



ROTARY CUT VKNEERS 



There is no better Hircli Rrown than that found on our 

 Timber lloblinRs. Send us a trial order for a crate or a 

 carload, and wc are confident you will forward repeaters 

 without solicitation. Quality considered, you wifl tind 

 our prices reasonable. 



Bissell Lumber Company 



Address IJept. 3 

 MARSHFIELD, WIS. 



Mills: 

 TRIPOLI, WIS. 



Rotary Cut 



Northern 

 Veneers 



Members of 

 Maple Flooring 

 M.inufacturers* 

 Assoei.ntion 



FURNITURE manufacturers and factory buyers who insist on 

 having high quality veneers should send us their orders. We 

 ire specialists in Northern Veneers. , , ^ . 



We also manufacture Northern Pine, Spruce, Hemlock. Cedar 

 Posts and Poles, Lath an 1 Shingles, which we ship in straight 

 cars and cargoes or m sid with our "Peerless Brand" Rock 

 Maple, Beech or Birch Floorins. i,,'l t)in- /'»i.i'.v 



The Northwestern Cooperage & Lumber Company 



Chicago Offices: 812 Monadnock Block GLADSTONE, MICH. 



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RANGOON TEAK | 



B B T C L I 



British Honduras Mahogany | 



B. E. & P. CO. 1 



SPOT and SHIPMENT | 



QUALITY AND SERVICE I 



BUSK & DANIELS, 8 Broadway, NEW YORK J 



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Automatic Control of Humidity in Shops 



Devices for controlling humidity in shops are of three 

 types. The first are makeshifts, such as wet sawdust 

 strewn on the floor, troughs of running water at the sides 

 of the room, or simply an ordinary sprinkling can. Such 

 crude devices are not in any sense self-regulating, and 

 even with the most careful personal attention produce 

 only haphazard results. The sprinkling-can type of hu- 

 midifier has been in use for hundreds of years and is of 

 interest chiefly because it shows that the need for air-con- 

 ditioning apparatus in many industrial plants has been 

 recognized for a long time. A second class of humidifiers 

 ii:cludes those that are capable of increasing the moisture 



in the air up to the point for which they are set, but can- 

 not decrease it. When the weather forces the humidity 

 cbove the desired point, such instruments remain inactive. 

 Few instruments of this type attempt any control of the 

 temperature. A third type of conditioning apparatus is 

 tliat which is able to hold the atmosphere in a room at a 

 constant temperature and humidity irrespective of out- 

 side conditions. 



One of the few instruments which absolutely control 

 both the temperature and the humidity of the air is that 

 aeveloped at the Forest Products Laboratory, Madison, 

 Wisconsin. For several years this apparatus has main- 

 tained in the laboratory wood-parts storage rooms the 

 typical climatic conditions found in various parts of the 

 L'nited States, ranging from the hot, moist climate of the 

 South to the cold, dry climate found in the mountain 

 regions. The same type of instrument also keeps the 

 woodworking rooms at the laboratory at uniform tem- 

 perature and humidity year in and year out, with the re- 

 sult that the wooden articles manufactured there give 

 the minimum amount of trouble afterwards from warp- 

 ing and checking, and the shop conditions are healthful 

 rnd comfortable to the highest degree. These instru- 

 ments have required very little personal attention since 

 they were installed. 



The principle upon which the laboratory automatic 

 humidity-control apparatus works is that of cooling the 

 air to the dewpoint temperature for the desired atmos- 

 pheric condition, saturating it with moisture at that point, 

 and then heating it without addition of moisture to the re- 

 quired room temperature. For any given room temper- 

 by choosing the temperature at which the air is saturated. 



The apparatus consists of a small cabinet, or chamber, 

 ature it is possible to get any humidity desired, simply 

 through which the air is drawn as often as it needs to be 

 conditioned. The conditioning chamber contains water 

 sprays whose temperature is kept constant by a mixing 

 valve. These sprays suck in the air by their own action, 

 cool it to the temperature at which it should be saturated, 

 and give it all the moisture it can hold. As the air leaves 

 the chamber it is heated to room temperature by coils, 

 whose steam supply is controlled by a thermostat located 

 in the outlet. Thus when the air is drawn into the cham- 

 ber it may be too hot or too cold, too moist or too dry, 

 but the apparatus automatically humidifies or dehumidi- 

 fies it and brings it to the correct temperature before 

 ^;llowing it to pass again into the room. Both in the stor- 

 age rooms, where the air needs conditioning very in- 

 frequently, and in the workrooms, where it is completely 

 changed every ten minutes, the recording instruments 

 show that the atmospheric conditions have varied to only 

 a slight extent throughout a three-year period. 



This method of air conditioning was developed pri- 

 marily for woodworking shops and wood gluing, finish- 

 ing, and drying rooms. it is adaptable, however, to 

 numerous other industrial plants, including textile mills 

 and chemical, foodstuff, and tobacco factories, in which 

 close control of atmospheric conditions would be bene- 



