I'rbruarr SS, 101 il 





Operating a Progressive Kiln 





Bometimn a vUilor eoniM in eonlart with an op«nilor who ii Veen 

 for lb* ■ ' .... ,fjp, ^^ fl„,j mij 



whr, >■ ' '""C "CO- Up 



di ' 



of 



more .t 'l "l "''^ oilier 



time. I 



The kiln uiwhI wa« of the "pt fltteJ up with aovon 



four-foot e«r». Thin cnm in the temper- 



ing kiln, and when nn nk, bfiMWood or pop- 



In: ' (of one-inch liimlior. 



\V 11(1 not to be dry by 



the Uuio il it wnn run 



out on a ti t" ll'o *'"=■ 



tory «nJ then returnc<l to the kiln before it wnji Biirticicntly cooled 

 down to do any damage. 



The process of drying lumber consisted of first, exposing it to 

 direct action of a low pressure of steam ; second, gradually displncing 

 the steam witli dry heat from a hcnting coil; third, gradually or pro- 

 gressJTely n- i.ird the unloading p^ul of 



the kiln wit -o and the humidity grow- 



int; lo«s as the luniluT iippruuclidi llie linnr. 



The si>ccial features wore Uie grading of the temperature and 

 humidity from the loading end to the unloading end to suit the con- 

 ditions of the lumber at the different stages. The aim was to carry 

 a sufficient humidity in the kiln that high temperatures might be 

 maintained and these two elements when worked out carefully pro- 

 duced very rapid and successful drying. When the lumber entered 

 the kiln it was comparatively green and had to bo stenm-.-sprayed 

 strongly at a temjieraturc of 1-10 degrees until the registering instru- 

 ment showed a relative humidity of CO to lOOTc and the nearer to 

 100% the better to complete saturation, or as damp as possible without 

 staining the lumber at the piling sticks. 



• To avoid friction and produce easy running cars, each bunk was 

 set with the right hand flange of the wheels against the side of the 

 T-rail. This insured perfect alignment of each, and when the car 

 was started forward it equalized itself upon each rail. 



Particular attention was paid to the piling sticks, which were all 

 of a uniform thicknc-s. They were placed at frequent intervals so 

 that it was an assured fact that the himVier would come out straight. 

 The number used in each course varied from three to nine, according 

 to the kind and condition of the lumber. 



In piling the stock on the bunks forming the cars, care was taken 

 to make a flue three or four inches wide up through the center of the 

 load to within a few courses of the top. This flue aided very much in 

 equalizing the heat through the entire load. 



When it came to placing the cars in the kiln, nil the inlet dampers 

 .ind doors were closed as tightly as )>ossible, and the dampers in the 

 stacks set about half open. Since the heat on the coils was con- 

 tinuous, running the usual temperature from 110 to 170 degrees, it 

 was only necessary to turn on the steam spray strong for fifteen to 

 twenty minutes, or until the registering instrument showed the hu- 

 midity close to ninety per cent. The volume of spray was then reduced 

 so tha» ■ -.^mained at about this point. The temperature, 



under ' •. would rise quickly but the steam was kept 



on sufljcient to mnintain the ninety per cent or even more, since it was 

 desirable to raise the tcmf>erature to nearly the same degree that it 

 was in the main part of the kiln. This quick high temperature made it 

 necessary to carry great humidity in the tempering kiln. In the 

 language of the operator, "This is the necessary element, that the 

 humidity should come from the lumljcr and not from the spray. To 

 determine this, gradually reduce the amount of steam coming from 

 the spray piping until it is certain that the lumber is throwing oflf the 

 moisture and is able to hold the humidity." 



Since the tempering kiln is arrangctl to hold twice as many ears 

 as the kUn can dry daily of inch oak, by putting as many cars in 

 daily as are taken out at the unloading end, each car gets forty-eight 



hours for softening tho lumU-r. For ash, basswuod, etc., the timi in 

 the teni|H>ring kiln is only Inentyfour hours and this would neccusi- 

 late nil the ears uoing forward at the same time, thus drying the 



i for one ineh oiik, while for two- 

 i-ase, and there would bo only one 

 iiir i-vcry otlict diiy. 



When tho car was ready to move forward to the main l)ody of the 

 kiln it WHN kept »t tho damp end of the large apartment, lieing al- 

 lowed to move forward only us other cars camo through from day to 

 day to push it forward. Case-hardening would be the result if a rnr 

 that was damp and steaming were sent directly to the dry end of the 

 kiln. 



As the cars entered tlir- ni:iin kiln it was necessary to raise tho 

 humidity in this section to sixty per cent at the unloading end, ami 

 this was attended to each time the doors were 0|iened and cars sent 

 forward. When the cars were within two days of the dry end, the 

 humidity at tho unloading cml was reduced to thirty or forty |ier cent. 



Tho operator in question was getting tho best results. Ho was 

 following the instructions of the maker of the kiln but also using 

 his head. lie had tho inslninients for testing shrinkage, moisture in 

 the lunilier and tho humidity, and ho used them, as should any 

 Ofieralnr who expects to get the results necessary to do good cabinet 

 Vork. O. H M 



The Apple Pine 



Ranging eight hundred milis north iin'i Fouth along tho high 

 mountains of California grows the apple pine. Tliiit name never 

 found its way into oflicini lists in tree publications, but that is the 

 name by which woodsmen know it, and they know the tree so well that 

 they never make a mistake in its identification jirovided they can ap- 

 proach the tree and examine it. That is remarkable when it is con- 

 sidered that expert dendroIogi^ts who depend on the usual organs of 

 identificiitiou, the leaves, floivcrs, fruit, bark, and twigs, have had 

 uianj' a set-to and disjiute among IhcniKclves when called upon to 

 give this tree its correct name. If given plenty of time to figure on 

 the problem, the scientists will pronounce the tree Pinus jnffreyi, or 

 in plain English, Jeffrey pine; but before tho final conclusion is 

 reached they ni.iy tentatively call it Pinus ponderosa, or possibly 

 Pinus poiidcrosa scapular um; but the mountaineer will catch a nearer 

 way to identification and gi\c it a shorter name, without so much as 

 looking at leaf, flower, cone, or seed, and he will do it in a quarter 

 of the time required by tho botanist to unpack his microscope to 

 make nn examination. 



The tree is identified by it.^ odor, which once learned is never for- 

 gotten. The mountaineer's trained nose is pressed close in a deep 

 crevico of the bark, and the odor of an apple tells tho story. No 

 other known tree of that region has a similar odor, so there is no 

 mistake. The yellow pine (pondcrosa) which looks so much like the 

 apple pine as to keep the botanist constantly on his guard against 

 mistaking one for the other, smells simply like pine bark, and never 

 fools the mountaineer. 



The odor of the apple pine did not escape the keen observation of 

 .Sudworth ; but in his book he located the odor in the twigs and 

 said it resembled violets. The twigs are usually about a hundred 

 feet above the ground and quite out of reach and smelling distance 

 of the ordinary observer; but the bark of the trunk is always acces- 

 sible and quickly identifies this interesting pine of the high Cali- 

 fornia mountains. 



As a lubricant to u.sc on ;iii oil stone, kerosene oil gives the best 

 results, as it not only enables the stone to "take hold," but also 

 keeps it clean and prevents i' '" ■ ""ing up. 



A wood chopper can work liard tiioiigh to keep himself warui, but 

 if a wood finisher is expected to do so his work is not apt to be income 

 producing. 



