40 BULLETIN 1037, U. S. DEPARTMENT OF AGRICULTURE. 
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. 23 (Weiss, 56, p. 18-20.) 
23 A certain species of beetle, Dendroctonus ponderosae Hopk., has been mentioned by 
Von Schrenk (.$1) as being partly responsible for the dissemination of the spores of the 
blue-stain fungus. 
