112 REPORT OF NATIONAL MUSEUM, 1923. 



be compelled to stop manufacturing in a few years because of increas- 

 ing scarcity of the animals producing these raw products. A con- 

 siderable portion of the past year has been spent in rearranging and 

 relabeling these collections in order to give them a modern and 

 attractive appearance and bring out to better advantage their edu- 

 cational value. Four entirely new exhibits in this section were 

 installed. These illustrate the manufacturing processes and uses of 

 Pyralin, Bakelite, cellulose acetate, and fabrikoid, which are prod- 

 ucts developed to take the place of such materials as ivory, tortoise 

 shell, amber, horn, leather, etc. The older collections have been 

 regrouped and arranged in such a way as to have the real articles 

 as near the newer substitution products of the chemical industries 

 as possible, and thus give the visitor an opportunity to compare and 

 study the real and long-used organic raw materials with their mod- 

 ern industrial substitutes. All of' these interesting collections were 

 placed in cases on the east side of the Southwest court gallery. 

 After installing the new exhibit of Pyralin, it was found that the 

 afternoon sun shining on this material would in a short time affect 

 the color of the specimens, making it necessary to move this collec- 

 tion to the north side of the gallery. This change required rearrang- 

 ing nearly half of the exhibits in the gallery. Care was taken in the 

 rearrangement so that only such materials as were least affected by 

 sunlight were installed on the east side of the gallery. 



Five new permanent installations were set up in the section of 

 wood technology during the year, a special temporary exhibit, and, 

 in addition there was an entire reinstallation of five other exhibits. 

 A wagon and automobile wheel exhibit was placed on opposite sides 

 of a diaphragm case to bring out the fact that the wheels of these 

 two types of vehicles are constructed in a directly opposite manner. 

 The wagon wheel is made from hub to felloe, the spokes being driven 

 into the hub, and the wood felloe assembled after the wheel has been 

 cut to height and the spokes round tenoned. In the automobile wheel 

 the felloe is dressed and finished, spokes are driven into the felloe 

 and the two halves assembled into a perfect wheel ready to be 

 turned off to receive the permanent felloe band and the hub. The 

 other new installations included an exhibit of " Woodisk " wheels, 

 showing how a laminated wood wheel is built up and shaped for 

 use on both heavy duty and pleasure automobiles ; a case demonstrat- 

 ing the ravages of the white pine blister rust and methods for its 

 control; an exhibit showing the manufacture of double-tipped 

 matches; specimens of the insulating material sold as "Balsam- 

 Wool " ; and photographs representing typical lumbering operations 

 in Southern yellow pine. April 22-28, having been designated b}^ the 

 President as Forest Protection Week, this section made a special 

 effort to bring the need for forest protection before the public by 

 arranging a temporary exhibit picturing this branch of forest work 



