94 REPORT OF NATIONAL MUSEUM, 1925 



machine, and a section of an adding machine. The latter permits 

 the visitor to see the mechanism involved in this particular type 

 of calculator. These machines, with one of the earliest types of 

 adding machines invented by William Burroughs, which was pre- 

 sented to the Museum by the company nine years ago, form a fairly 

 complete visual record of the development of one of the distinct 

 types of calculating devices in use at the present time. 



In the section of communication the subject of writing machines 

 and typewriters includes at the present time a fairly complete rec- 

 ord by means of original machines of the development of the type- 

 writer. The Museum received as a gift from the Corona Typewriter 

 Co. during the year a series of three small-size, portable writing 

 machines, which represent periods in the development of the portable 

 type of writing machine, beginning with the machine of 1906 and 

 ending with the type used in 1925. 



The Automatic Electric Co., Chicago, 111., which last year pre- 

 sented an operative unit of the Strowger automatic telephone, 

 added to the exhibit this year a series of four automatic telephone 

 switches of the periods of 1896, 1903, 1913, and 1925, respectively. 

 These switches portray vividly the course of development of this 

 very interesting method of communication and demonstrate quite 

 forcibly that automatic telephony is the result of careful, deliberate, 

 and slow development rather than the product of accidental 

 discovery. 



For addition to the section of land transportation there was re- 

 ceived from Mrs. Lansing Van Auken, Watervliet, N. Y., an origi- 

 nal Knox automobile, made in 1900. The Knox automobile was one 

 of the first commercially successful automobiles of American manu- 

 facture and was used quite extensively for a number of years both 

 for passenger carriage and for general delivery of light merchandise. 

 Its particular feature was that it possessed three wheels, two in the 

 rear and one in front, and was operated by a single cylinder, air- 

 cooled engine located over the rear wheels. 



The signal section of the American Railway Association pre- 

 sented 16 specimens for addition to the exhibit of railway signaling 

 apparatus begun by that association in 1923. The specimens are 

 of obsolete design but are of great value when used to visualize the 

 development of the art of railway signaling. The work of securing 

 these historically important pieces is being carried on by H. S. 

 Balliet, secretary of the section, who has the cooperation of the 

 signal departments of the various railway companies. Thus far 

 the exhibit includes apparatus used on the Illinois Central, the 

 Louisville and Nashville, the New York, New Haven and Hartford, 

 the Pennsylvania, and the Southern Pacific Railroads. Signaling 



