﻿KILN DRYING HANDBOOK. 63 



in the run; (18) running record of appearance of stock, stress de- 

 terminations, and steaming and high humidity treatment; (19) final 

 condition of stock. 



The charts from the recorders, with run number, dates, and cor- 

 rections plainly indicated on each, should be filed with each run 

 report, and final-stress sections can frequently be kept to advantage, 

 at least until the stock has been worked up. To make the marking 

 of kiln samples simpler, it is suggested that each one bear the run 

 number and an additional individual serial number. Thus, if there 

 are four samples in run 32, they should be numbered 32-1, 32-2, and 

 32-3, 32^, respectively. Moisture sections cut from the sample 

 should bear the sample number and also an individual identifying 

 number or letter. The two sections first cut from 32-1 might be 

 32-1A and 32-1B and the final section 32-1C. 



ESSENTIAL APPARATUS. 



In order to work effectively, every operator should have certain 

 apparatus described in this handbook, and a suitable room or office 

 in which to keep and use it. The following list represents the mini- 

 mum compatible with efficient work : 



One standard-grade etched-steni glass chemical thermometer, 30° to 220° F., 

 graduated in degrees. 



Six wet and dry bulb hygrometers, 60° to 220° F., graduated 2 degrees. 



One balance or trip scale for weighing moisture sections, capacity 1 kilogram 

 (1,000 grams=2.2 pounds, about) sensitive to 0.1 gram, with sliding poise on 

 arm for weights up to 5 grams. Brass weights, 1 gram to 1,000 grams in box. 



One platform scale or balance for kiln samples. Platform balance capacity 

 100 pounds, sensitive to 1/100 pound. Beam graduated to 1/100 pound; or — 



Solution scale, capacity 20 kilograms, sensitive to 1 gram ; 2 scalej)eams, one 

 graduated to 100 grams in 1-gram units, the other graduated to 1,000 grams in 

 100 gram units; counterpoise and loose weights. 



One drying oven (electric or steam) inside dimensions at least 10 by 12 by 

 10 inches. Thermostatic control on electric oven sensitive to 2° F. To operate 

 at 212° F. 



One 10-inch slide rule. 



One smoke box with concentrated ammonia and hydrochloric acid. 



Two flash-lamps ; spare batteries and lights. 



One gas plate and kettle for heating pitch. 



Miscellaneous tools, such as saw, screw drivers, hammer, rule, etc. 



AIR SEASONING. 



It is not within the province of this bulletin to discuss the air 

 seasoning of wood, except in so far as a knowledge of it is essential 

 to the kiln operator. Much of the lumber dried in kilns, especially 

 hardwood lumber, is first air dried, either at the sawmill or the 

 manufacturing plant, and the quality of the finished product de- 

 pends in no small measure upon the care taken in the preliminary 

 air seasoning. 



The following general rules apply in piling the stock in the yard 

 for seasoning: 



Foundations for piles should be firm and solid, level in one direc- 

 tion and properly pitched in the other, well above the ground and 

 free from weeds and decay. 



Stickers should be of uniform size, not over 2 inches wide nor less 

 than seven-eighths inch thick, free from decay, and planed on two 



