August 25, 1919 



HARDWOOD RECORD 



21 



The following series of instructions for determining the moisture 

 content of wood and the use of kiln samjjles was prepared by L. K. 

 Pomeroy of the government laboratory, Madison, Wis.: 



Cut a cross section about %" wide at a point not less than one 

 foot from the end of the board or plank to be tested. Do not cut 

 sections less than one foot from the end, because the ends of a 

 board are affected by end drj-ing, and a test piece from near the 

 end would not be representative of the entire board. 



Remove all splinters from the surfaces of the section, and weigh 

 the section on a sensitive balance immediately after sawing. 



Record the weight of the section on the section at the time of 

 weighing. 



Place the section on a hot steam pipe, radiator, cylinder head, or 

 preferably in a drying oven heated to 212° F. 



Reweigh the section when thoroughly dry. (If, after several 

 hours, the piece no longer loses weight, it may be considered thor- 

 oughly dry.) 



The first weight minus the second weight represents the weight of 

 the water removed from the wood. 



Divide the weight of the water by the second weight or dry 

 weight of the wood and multiply the result by 100. 



The value obtained is the per cent moisture content of the wood 

 based on the dry weight of the wood. In order to obtain the aver- 

 age moisture content of a pile of lumber, select several representa- 

 tive boards and determine the moisture content of each board as 

 above. 



Preparation of Samples for Kiln Run 



To provide samples for a kiln run, select several boards repre- 

 sentative of the stock to be put in the kiln. Number the boards and 

 mark off and saw out samples in the following manner: 



^ S/8" section ^ 3/8" section 



Sample board 



TT 



^ 



Sample 

 Z' > 



Number the %" sections and 2' samples with the number of the 

 sample board from which they are cut. Determine the moisture 

 content of the sample boards according to instruction given in a 

 former paragraph. Take the average moisture content of the two 

 %" sections cut from the ends of the 2' samples as the moisture 

 content of the board. 



Paint the ends of the 2' samples with a heat and water-resistant 

 paint or dip them in a mixture of rosin and lampblack. In prepar- 

 ing the rosin and lampblack for end dip purposes mix 60 parts rosin 

 (by weight) with 1 part lampblack (by weight), and heat to the 

 melting point. Dip the samples in the hot solution to form an even 

 coating over the ends. 



Determining Dry Weight of Sample 



Having determined the moisture content of the sample board by 

 means of %" moisture sections, proceed in the following manner to 

 determine the calculated dry weight of the sample: 



Weigh the green sample. 



This weight equals the amount of wood and water in the sample. 



Assume that the sample has the same per cent moisture content 

 as the %" section. 



Let 100 per cent equal the amount of wood in the sample. 



Add this 100 per cent to the actual per cent moisture content of 

 the sample. 



Divide the total weight of the sample by the 100 per cent wood 

 plus the per cent moisture content of the sample. 



The result will be the dry weight of the sample. This value is 

 only a calculated number but should represent, if care is taken in 

 making weights and calculations, the weight of the sample after all 

 the water is out of it. 



The Instructions Illustrated 



Oreen sample 

 board 



<cf 



3/8" section /fZ/S" section 



10.00 lbs. 



Sample 

 < 2'— 



<f 



Green weight of two %" sections = 350.5 grams 



Dry weight of two %" sections = 195.0 grams 



Water taken out of sections in drying = 155.5 grama 



Weight of water, 155.5 grams, divided by weight of wood, 195.0 

 grams, equals 0.797. 



0.797 multiplied by 100 equals 79.7 per cent moisture content of 

 %" sections. 



Then the moisture content of sample is 79.7 per cent. 



Green weight of sample = 10 pounds. 



Add: 100.0% amount of wood in sample. 



79.7% amount of moisture in sample. 



179.7% amount of wood and moisture. 



Divide total weight of the sample, 10 pounds, by the total per- 

 centage of wood and moisture, 179.7. 



The result equals 5.57 pounds, which is the calculated dry weight 

 of the sample. 



Finding Average Moisture Content 



Following is a method of procedure to determine the average 

 moisture content of the kiln charge at any time of the run, by use 

 of samples: 



Place the samples in the piles in different parts of the kiln so 

 that they may be as nearly as possible representative of the entire 

 charge. 



Weigh the samples at regular intervals during the kiln run. 



Subtract the calculated dry weights of the samples from their 

 respective kiln weights (the weights obtained during the kiln run). 



The difference between the kiln weight and the calculated dry 

 weight of the individual samples is the weight of the moisture in 

 the samples. 



Divide the weight of the moisture by the calculated dry weight 

 of the sample and multiply the result by 100. The result obtained 

 is the moisture content of the sample. 



The average moisture content of all of the samples in the kiln will 

 represent the average moisture content of the entire charge. 



Determining Conditions of Stock 



Moisture condition tests can be made as follows to determine 

 whether the stock is thoroughly and evenly dried to the center: 



Cut a %" section similar to the regular moisture test sections. 



Cut a thin shell about %" thick from around the outside of the 

 piece. 



Saw out a piece about Y-z" thick from the center of the same 

 section. 



Weigh the outside pieces together immediately after sawing. 



Weigh the inside piece immediately after sawing. 



Dry the pieces and re-weigh. 



Proceed to tind the per cent moisture content of the outer shell 

 and center piece separately, as exjjlained in the foregoing instruc- 

 tions. 



Outdoor Billboards Condemned 



The National Association of Real Estate Boards in convention 

 at Atlantic City unanimously condemned outdoor billboard adver- 

 tising. That action bears the earmarks of a boomerang — something 

 likely to hit the one that set it in motion. The ordinary observer 

 has been of the opinion that real estate dealers have been the worst 

 offenders, if billboard advertising is an offense. Vacant lots are 

 often covered with signs of sale nailed on posts. However, if the 

 real estate men are aiming at their own practice in advertising, 

 the general public will gladly see the little sale signs come down 

 from the posts. Perhaps they are aiming at larger game and are 

 seeking the end of the enormous billboards set up by tobacco 

 dealers, clothiers, and other large manufacturers. They are familiar 

 features of the landscape along most trunk line railroads; and their 

 removal would often improve the appearance of the landscape. 



What effect, if any, would the elimination of such billboards have 

 on the lumber business? The builders of these boards buy a lot of 

 lumber, and if no boards are built, the lumbermen's sales will be 

 lessened by that much. Wooden signs, which do not include the 

 large billboards, call for 6,888,366 feet of lumber a year in this 

 country, according to statistics published by the government; and 

 this cannot be more than a fraction of what the big billboards use. 



If outdoor advertising is done away with, many an advertising 

 campaign will have to be planned anew. 



