40 



BULLETIN 1037, U. S. DEPAETMEISTT OF AGEICULTURE. 



in the yard. There they were unloaded, close piled, and allowed to 

 remain until ready for shipment. 



During the dipping operation it was observed that in some cases 

 as many as 10 to 15 per cent of the untreated spokes in a given truck 

 load showed the presence of sap-stain. In one lot the number show- 

 ing sap-stain and mold was estimated at 50 per cent. Other lots 

 were practically free from fungi. During the experimental work 

 the weather was for the most part hot and dry. Following one or 

 two light showers the amount of mold on untreated material showed 

 a marked gain. 



The methods of dipping were similar for all baths except in the 

 case of the hot creosote. Here, the steam coil was employed and a 



Fig. 18. — The experimental dipping of red-oak spokes green from the lathe. 



temperature of 150° to 155° F. maintained. One barrel served for 

 both cold and hot creosote. The borax was dissolved by aid of the 

 steam coil in the .second barrel. A third barrel was necessary for 

 the mercuric-chlorid dip. Thermometer and hydrometer readings 

 were taken at frequent intervals, and whenever necessary correc- 

 tions were made to maintain a constant temperature, and concentra- 

 tion in the bath. 



Incidentally, it was noticed that ambrosia beetles were very 

 quickly killed by the creosote dip, a point of importance to consider 

 in controlling insect pests which at times, especially during warm 

 and damp weather, are said to cause considerable losses in piled 

 lumber.-^ (Weiss, 56, p. 18-20.) 



'" A certain species of beetle, Dcnclroctonus ponderosae Hopk., has been mentioned by 

 Von Schrenk (il) as being partly responsible for the dissemination of the spores of the 

 blue-stain fungus. 



