PREFACE. 



In the year 1884 a Section of Transportation was organized in 

 the United States National Museum for the purpose of preparing 

 and assembling educational exhibits of a few objects of railroad 

 machinery which had been obtained both from the Centennial Ex- 

 hibition held in Philadelphia in 1876 and still earlier as incidentals 

 to ethnological collections, and to secure other collections relating 

 to the railway industry. 



From this beginning the section was theoretically enlarged to in- 

 clude the whole field of engineering, but it has actually enlarged 

 in the fields of mechanical engineering, especially the early develop- 

 ments of the steam engine, locomotive, and internal combustion en- 

 gine; electrical engineering, particularly the development of the 

 telegraph, telephone, and the electric light; metrology, particularly 

 horology; and naval architecture. 



The primary object of these collections is to visualize broadly 

 the steps by which advances have been made in each field up to 

 the present day; to show the layman the fundamental and general 

 principles which are the basis for the developments, and to familiar- 

 ize the engineer with other branches of engineering than his own. 



While this purpose has been continually in mind to those in 

 charge, an examination of the collections will show that none of 

 them has reached the goal. Some lack the starting points; others 

 have certain portions of their development completed ; and but few 

 may be said to be up to date. Many reasons might be given for 

 this condition of affairs, the chief ones being : 



1. The Museum is dependent almost wholly upon gifts or loans 

 for augmenting its collections, and while those in charge know what 

 objects are desirable, the general public does not. 



2. Funds for the employment of preparators, model makers, etc., 

 are limited, so that the completion of the collections in this way 

 is a slow process. 



3. Limited exhibition space, which has prevented in some instances 

 the acquisition of objects of particular value to the collections. 



The general limitations of the collections as noted are applicable 

 to the mechanical engineering collection, and this catalogue is pre- 

 pared in the belief that an acquaintanceship with the collection 

 as it now stands will lead to the cooperation necessary to make it 

 complete. 



C. W. M. 



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