94 REPORT OF NATIONAL, MUSEUM, 1924 



Co., Ambler, Pa-., donated 12 specimens representing steps in the 

 process of producing commercial asbestos fiber. 



WORK OF PRESERVING AND INSTALLING COLLECTIONS PRESENT CONDITION OF 



COLLECTIONS 



The major operations of installation made during the year were 

 confined to two sections, namely, communication and aircraft. To- 

 ward the close of last year over a thousand objects pertaining to 

 telegraphy, telephony, and radio were transferred from the War 

 Department, Signal Corps, and the work of cataloguing, installing, 

 and labeling 'this collection of objects has required most of the 

 time of the two out of the three members of the staff available. 

 When not engaged upon the communication collections these same 

 two members devoted their time to the installation of aircraft and 

 other objects which were secured during the year to augment the 

 aircraft collections. At this writing none of this work can be said 

 to be completed; there is still remaining the final numbering and 

 rechecking of the objects comprising these major collections. The 

 third member of the staff has the primary duty of maintaining the 

 mechanically operative models and exhibits. The number of this 

 type of exhibits is increasing annually and is consequently increasing 

 the percentage of time which the preparator must spend on this work 

 and decreases the amount of his time available for other purposes. 

 For this reason, therefore, the. model showing the mining and prep- 

 aration of land pebble phosphate mining begun last year was not 

 completed until January of this 1 year, and time was found to con- 

 struct but 10 additional models for the exhibition series begun last 

 year relating to mechanical powers, motions, and devices. Addi- 

 tional time, when it was available, was spent in making repairs on 

 the older collections. This work involves a variety of operations, 

 including the renewal of sails' and rigging on boat models, making 

 and replacing worn-out parts both of wood and metal on working 

 models, renewing broken parts of other models and exhibits, and 

 repairing and painting broken exhibits in plaster. 



The model mentioned above, visualizing the land pebble phos- 

 phate mining industry, is constructed entirely of planter and wood, 

 the topographic features being modeled in plaster and all super- 

 structures made in wood. The model is 16 feet long and 30 inches 

 wide and made to a scale of 20 feet to the inch. The main feature 

 of this industry is the mining of the pebble phosphate by hydraulic 

 methods, using enormous streams of water to wash down the banks 

 of phosphate pebbles and collect the washed material in a depression 

 where electrically driven pumps carry it to a washing, drying, and 

 screening plant. The model of the natural pitch lake on the island of 



