230 THE COLLECTION OF BOTANICAL SPECIMENS 



dry weather only one folded dryer is required for ordinary herbaceous 

 plants of temperate climates, provided the dryers are changed twice 

 or even thrice a day. In bad weather, or with thick, water-laden speci- 

 mens, or when the plants must remain more than twenty-four hours in 

 the dryers without change, four folded dryers are required. By using 

 a large number of dryers in the best of weather, it is frequently possible 

 to dry ordinary specimens with but one change of dryers; or even without 

 change, to secure specimens of the first quality. 



Powerful pressure should next be applied. Weights, screws or levers 

 may be employed for this purpose, but no other method is equal to 

 the use of straps. These should be made of the heaviest and best 

 leather obtainable, should be li or li inches in width and provided 

 with a large strong buckle, the holes not more than two inches apart 

 and punched to within two feet of the buckle. The length of the straps 

 should be proportional to the size of the bundle drying. For extensive 

 collecting, straps of 8 feet are required. The straps should be laid only 

 a few inches apart and the bundle laid upon them so that the buckle 

 barely projects from under the edge. The straps should be drawn 

 firmly into place without drawing the buckles from their place. The 

 operator now stands upon the bundle and stamps it firmly at all points, 

 so that no parts of the specimens are left without a firm application 

 of the dryers. The straps are then drawn as tightly as possible and 

 secured. A strong man can thus secure pressure of 500 or 600 pounds, 

 all of which is required for a pile of dryers two feet or more in height. 

 Even then it will be found, after the lapse of two or three hours, that 

 the pressure has become almost completely relaxed, owing to the wilting 

 and shrinking of the specimens^ and the straps must be tightened. 

 The pile should now be stood upon the end on a dry stone or wooden 

 support, a pole frame being best. The flat side should be exposed to the 

 sun, or quite as good, to the heat of the kitchen range. When possible, 

 the dryers should be changed twice a day for the first day or two. The 

 dryers into which the sheets are to be transfen-ed should be perfectly dry 

 and if possible hot from the sun. When it is not possible to expose them 

 to the sun just previous to making a change in the morning, they should 

 be wrapped tightly in a rubber cloth when brought in from the sunshine 

 of the previous afternoon, as dryers not thus protected will absoTb a 

 considerable amount of moisture during the night. It is to be con- 

 sidered that the first hour in perfectly dry, hot dryers contributes quite 

 as much to the beauty of the specimens as the succeeding five hours. 



In making the change, the specimen sheets are to be transferred to 



