H A K & W OO D -RECORD 



25 



United States and inferior only to Turkish boxwood, which has 

 become so expensive that shuttlemakers cannot use it. 



In New Hampshire many woods are used for spools. Most of 

 the one-piece spools are of paper birch, but varying amounts of 

 other birches and maples are used. White birch, which in New 

 England is often called oldfield or poverty birch, is coming into use 

 as spool wood. This is a matter for congratulation, for it has 

 generally beeu looked upon as somewhat of a nuisance where it 

 grows in great abundance, on account of its small size and its habit 

 of overrunning the country. 



Chair makers use more red oak than any other wood; beech is 

 second, and sugar maple a close third. Most of the white oak 

 reported was shipped in from the Ohio valley. Half a million feet 

 of chestnut went to the chair factories, much of it going into mission 

 pieces. Its fuming qualities are higher than most woods. Through- 

 out New Hampshire factories generally red oak is more important 

 than white oak. It costs more and more is used. Chair makers 

 often stain them and ash to imitate oak. 



The clothespin factories are kept busy with beech. Birch and 

 maple are used also. Half a million bent rims for bicycles, auto- 

 mobiles and racing sulkies are made yearly. Sugar maple, yellow 

 birch and beech are the woods used, with maple leading. 



New Hampshire is strong on shoepegs. About 2,500,000 feet of 

 paper birch is used yearly in producing this commodity. The wet 

 pegs are bleached with sulphuric acid and are then tumbled and 

 sifted to free them from splinters. They are measured by the bushel. 



White pine to the extent of about 140,000 feet a year is manu- 

 factured into "tongue depressors." This article has nothing to do 

 with wagons, as might be inferred from the name, but is a small 

 instrument of late invention used by doctors in examining throats 

 of patients. They formerly used a silver instrument, but for sanitary 

 reasons that has been discarded and those of cheap pine have been 

 substituted. The article is used only once and is then destroyed. 



New Hampsfiire manufacturers found out in some way that aspen 

 makes a capital handle for an oyster-shucking knife, because it is 

 absorbent and never becomes slippery. They have built up a little 

 industry in making such handles. About 20,000 feet of aspen is 

 used yearly, which is good for 300,000 handles, which would seem 

 to be sufficient to supply the shuckers of forty states. Vast numbers 

 of very small handles of other kinds are made, such as those for 

 shoe knives, gin\lets, corkscrews, curling irons, awls, screwdrivers, dip- 

 pers and pails. Makers of handles for rakes, hoes and shovels in 

 New Hampshire are using beech, birch and maple, while makers of 

 these articles in the South and West depend largely on ash. 



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Experimental Kiln-Drying 





The Forest Service has issued bulletin 104, from the laboratory at 

 Madison, Wis., dealing with the principles of drying lumber at atmos- 

 pheric pressure. It is the work of Harry D. Tieman, in charge of 

 timber physics. It pretends to be nothing more than an investi- 

 gation of principles which govern the proper drying of lumber in 

 kOns. It is stated that the series of experiments has not yet been 

 completed, and that this bulletin is a progress report issued to 

 answer numerous inquiries which are being constantly received at 

 the laboratory. 



Mr. Tieman has built a sample dry-kiln for carrying on experi- 

 mental work. It is constructed with complete apparatus for regu- 

 lating the temperature, governing circulation of air, and controlling 

 the degree of moisture maintained in the air. He has been granted 

 four patents on his processes, and these patents have been dedi- 

 cated to the public, so that whatever good there is in them will be 

 free to whoever wishes to use them. 



The bulletin is both practical and technical. Part I deals with 

 the subject in the ordinary language of lumbermen; while Part II 

 is evidently intended for engineers who wish to make a thorough 

 scientific study of the principles involved. 



What the author calls the basic principles of kiln-drying are set 

 down as follows: 



Timber should be heated through before drying begins. 



Air should be very humid at the beginning of the drying process, 

 and be made dryer only gradually. 



The temperature of the lumber must be maintained uniformly 

 throughout the entire pile. For this an exceedingly large circulation 

 of air is essential. 



Control of the drying process at any given temperature must be 

 secured by controlling relative humidity, not by decreasing circulation. 



In general, high temperatures permit more rapid drying than do 

 lower ones. The higher the temperature of the lumber, the more 

 eflScient is the kUn. It is believed that temperatures as high as the 

 boiling point are not injurious to most woods, provided aU the other 

 fundamentally important factors are taken care of. Some species, 

 however, may not be able to stand as high temperatures as others. 



The degree of dryness attained, where strength is the prime 

 requisite, should not exceed that at which the wood is to be used. 



When the wood can stand the heat without detrimental effects 

 for the intended use, preliminary steaming, not in condensed but in 

 live steam, is beneficial. 



Tlie pressure and duration of steaming desirable in kiln-drying are 



points which have not yet been thoroughly worked out. From five 

 minutes to twenty-four hours, or even longer, and pressures ranging 

 from atmospheric to fifty pounds gauge have been used in piactice. 

 The higher the pressure, the greater is the effect produced, and 

 the longer the time, the more thoroughly the treatment penetrates 

 the wood. Experiments have shown that a pressure slightly above 

 atmospheric for twenty-four hours is sufficient to slightly darken 

 two-inch maple clear through, and a pressure of forty pounds that 

 length of time will turn oak, and probabh- other hardwoods, almost 

 black. The organic materials or sap in the wood are changed by 

 cooking, and apparently some undetermined chemical change takes 

 place. This is indicated by the fact that the color of the wood is 

 darkened, the degree of coloring depending upon the temperature and 

 duration of the process; and that the wood when subsequently dried 

 has lost some of its original weight and is less hygroscopic. The 

 change in hygroscopicity is beneficial for some purposes, as it reduces 

 swelling and shrinkage of the wood. Very rich color effects are pro- 

 duced in hardwoods by suflicient steaming. Any well-made kiln 

 which will fulfill the conditions required as to circulation and humidity 

 control should work satisfactorily; but each case must be studied by 

 itself and the various factors modified to suit the particular con- 

 ditions of the problem. In every new case the lumber should be con- 

 stantly watched and, if checking begins, the humidity should be 

 increased until it stops. It is not reducing the circulation, but 

 adding the necessary moisture to the air, that should be depended on 

 to prevent checking. 



The free water in green wood may be driven off rapidly by heating 

 the wood to the boiling point and supplying the heat necessary for 

 vaporization. This will not injure the wood, provided it is done in 

 nearly saturated vapor; hence the applicability of superheated steam 

 in drying lumber. 



Progress of Forestry 



Thirty out of forty-seven states have laws relating to forestry in 

 some form or another. In the remaining seventeen no provisions 

 whatever are made along this line. Out of the first thirty, seventeen 

 - have placed the administration of the forestry work in the hands 

 of trained foresters. Best results are secured where the forester's 

 office is kept untainted from political patronage. There are seven 

 states which accomplish this by having the forester appointed by a 

 non-political board of forestry. They are California, Kentucky, 

 Maryland, Minnesota, Vermont and Wisconsin. 



