1918] Nichols & St. John,— Corrugated Boards 159 



alone by the second and fourth. As to the relative merits of s. f. 

 ventilators plus driers versus d. f. ventilators, it should be said that 

 the results obtained with the former of these two equipments are quite 

 equal to those obtained by the latter, but the first, third, fourth and 

 fifth factors mentioned above are all in favor of the d. f. ventilators. 

 Using the first equipment it takes several days to dr\^ a load of plants, 

 while with the second a full capacity load can be turned out each day. 

 In this connection it should be remarked that the "Washington" 

 drier is far superior to the ordinary type in its greater absorbent 

 power, thinness, firmness, and strength. So far as bulk and actual 

 weight are concerned, equal quantities of s. f. ventilators plus driers, 

 on the one hand, and of d. f. ventilators, on the other, are about 

 equally matched: one hundred d. f. ventilators were foimd to weigh 

 28| pounds, as compared with 15f and 13 j pounds for the same 

 quantities of s. f. ventilators and Washington driers respectively. 

 But the great sa^-ing in both bulk and weight is seen when account 

 is taken of the speed with which results can be obtained by using the 

 d. f. ventilators. On an extended collecting trip a given number of 

 d. f. ventilators will turn out as many dried specimens as three or 

 four times their number of s. f. ventilators plus driers. Add to this 

 the greater convenience in handling and the superiority of the d. f. 

 ventilators can hardly be questioned. 



With regard to the use of artificial heat, it is our opinion, based on 

 several years' experience, that so far as the quality of results is con- 

 cerned no potent objection can be urg6d against it: on the contrary, 

 as earlier indicated, the specimens dried in this way are obviously 

 superior to those dried without heat. Moreover the saving of time 

 and energy and, in the field, of weight and bulk are big items. As to 

 the source of heat, for field work either a lantern or a fire is satis- 

 factory. It must be admitted, however, that a fire does require more 

 or less constant attention, and that on this account, where it is 

 practicable, a lantern is to be preferred, since, while it does not pro- 

 duce results quite as rapidly, the lantern requires much less super- 

 vision and can be left on duty day and night. 



For use in the laboratory the senior writer has found great satis- 

 faction in the following equipment. A rectangular wooden box about 

 three feet high and open at the top was constructed. The width of the 

 box is slightly more than the length of a pressing frame; its length 

 is immaterial, but is sufficient to accommodate a press about two feet 



