234 CARNEGIE INSTITUTION OF WASHINGTON. 



main shop area. A separate room is devoted to some of the smaller 

 machine-tools with which much of the work of the highest precision 

 is done. The pattern-shop has been moved into an extension built 

 at the rear of the carpenter-shop, so that the woodworking depart- 

 ment is now essentially separated from the machine-shop and the 

 fire risk is materially reduced. A well-equipped storage room for 

 shop supplies has been made from a portion of the old optical testing- 

 hall, and the small photographic dark-room has been remodeled into 

 a lavatory and locker-room for the employees of the shop. 



The following is a list of the principal machine-tools added to the 

 shop equipment during the year: 



No. 3 Cincinnati universal high-power milhng-machine, with independent motor drive 

 and heavy vertical milling attachment, universal milling attachment, cir- 

 cular railhng attachment with power feed and 7.5-inch high-speed inserted- 

 tooth milling cutter, in addition to regular equipment. 



No. 31 Lucas horizontal boring, drilling, and milUng machine, equipped with inde- 

 pendent motor drive, star feed facing head, plain circular swiveling table, 

 rectangular swiveling table with lock bolt, auxihary table, and 10-inch high- 

 speed inserted-tooth face mill. 



G. A. Gray extra heavy pattern 36-inch by 48-inch by 12-foot planer, with one head on 

 cross rail and one head on each housing, driven by direct connected slow 

 speed 7.5 H. P. Westinghouse motor. 



Mueller 3-foot standard radial drill with column extended one foot, equipped with worm, 

 swivehng, and round tables and independent motor drive. 



No. V2 Van Norman duplex milling machine, with index centers, collets, and vise and 

 independent motor drive. 



Knecht friction sensitive drill press, motor driven. 



Brown & Sharpe 30-inch by 36-inch surface plate. 



Crane, which serves assembling room, two drill-presses, and for loading and unloading 

 at shop entrance. 



Surface-grinding attachment for 24-inch by 24-inch Gray planer. 



A small shop has been equipped for Mr. Jacomini, chief instrument- 

 maker, in the basement of the new office building, where the conditions 

 are extremely favorable for work of the highest precision and delicacy, 

 on account of the massive walls and the constancy of temperature. 

 The new equipment installed in this shop is enumerated below: 



One 14-inch Pratt & Whitney lathe, 10-foot bed, motor drive. 



One 14-inch Barnes lathe, 8-foot bed, for grinding and lower grade work, motor drive. 



One Brown & Sharpe No. 2 A milling-machine, constant-speed motor drive. 



One Atlas sensitive drill, motor drive. 



One Hisey-Wolf pedestal grinder, motor drive. 



In the Hooker building the wooden floors of the small offices have 

 been removed completely and replaced by concrete, and a number of 

 the offices have been joined into single rooms suitable for optical 

 work. From these rooms several entrances lead into the main 

 testing-hall. A portion of the northern end of the testing-hall has 

 been transformed into a room for the grinding and polishing of the 

 60-inch plane mirror which is to be used in testing the figure of 

 the 100-inch concave mirror. Doors open from this room into the 

 testing-hall and in this way tests may be made upon both of the 

 mirrors by rotating them to a vertical position without the necessity 

 of moving them from their places. Smaller grinding and polishing 



