THE NAVAL STOEES INDUSTRY. 51 



EFFECT OF TEMPERATURE ON VOLUME OF TURPENTINE. 



Operators often complain that the factor's gauge of their barrels 

 is 1 or 2 gallons less than their own. When the barrel has not 

 leaked, the difference is usually due to the temperature at which the 

 turpentine was placed in the barrel. Very frequently the turpentine 

 is at a temperature of from 50° to 60° C. (from 122° to 140° F.) when 

 the barrels are filled, and later cools to, say, 25° C. The mean coeffi- 

 cient of expansion of turpentine between 10° and 40° C. is 0.000817 

 per degree. 1 By rough calculation, assuming a specific gravity of 

 0.8500 at 50° C, if the original 50 gallons have cooled 25 degrees, the 

 loss of volume by contraction will be about 1.2 gallons. 2 



When the condenser is incapable of cooling the distillate to ordinary 

 temperatures, the barrels after being filled with the warm turpentine 

 should be loosely plugged and allowed to stand several hours, or until 

 their contents have cooled to the temperature of the surrounding 

 atmosphere. The barrels may then be filled up to the required 

 volume. 



COST ESTIMATES ON A 20-CROP TURPENTINE OPERATION. 



The cost figures which follow do not apply to any single locality; 

 they have been derived from several sources, and are believed to 

 cover a fair range. 



The yields 3 have been calculated from the data contained in Forest 

 Service Bulletin 90. The dip is assumed to contain 15 per cent water 

 and trash and 18.5 per cent turpentine, and the scrape 10 per cent 

 trash and 11 per cent turpentine; while 1 gallon of turpentine is 

 assumed to weigh 7.25 pounds. 



1 Technologic Paper No. 9, Bureau of Standards, 1912. 



2 The following formula will give the expansion or contraction of turpentine due to temperature changes 



v= «v 



G±(T'-T) .000817 

 where G and V are the specific gravity and volume at the temperature T, and V is the volume at the lower 

 temperature T'. 



3 YIELDS PEE CROP, CALCULATED FROM FOREST SERVICE BULLETIN 90. 



First year— 31 chippings: 



83,495 lbs. dip, yielding 42. 8 bbls. turpentine and 199. bbls. rosin. 

 12,560 lbs. scrape, yielding 3. 8 bbls. turpentine and 35. 4 bbls. rosin. 



Total yield 46. 6 bbls. turpentine and 234. 4 bbls. rosin. 



Second year— 30 chippings: 



74,791 lbs. dip, yielding 38. 2 bbls. turpentine and 178. bbls. rosin. 

 14,818 lbs. scrape, yielding 4. 5 bbls. turpentine and 41. 8 bbls. rosin. 



Total yield 42. 7 bbls. turpentine and 219. 8 bbls. rosin. 



Third year — 29 chippings: 



57,324 lbs. dip, yielding 29. 3 bbls. turpentine and 136. 1 bbls. rosin. 

 13,399 lbs. scrape, yielding 3. 6 bbls. turpentine and 38. 3 bbls. rosin. 



Total yield 32. 9 bbls. turpentine and 174. 4 bbls. rosin. 



Fourth year — 30 chippings: 



45,100 lbs. dip, yielding 23. bbls. turpentine and 107. 1 bbls. rosin. 

 19,908 lbs. scrape, yielding 6. bbls. turpentine and 56. 2 bbls. rosin. 



Total yield 29. bbls. turpentine and 163. 3 bbls. rosin. 



