gg BULLETIN 173, U. S. NATIONAL MUSEUM 



FITTS GOVERNOR VALVE, 1859 



U.S.N.M. no. 30S662; original patent model; transferred from the United States 

 Patent OflBce; not illustrated. 



This model was submitted with the application for the patent 

 issued to Benaiah Fitts, of Worcester, Mass., August 9, 1859, no. 

 25005. 



The model represents a globular valve in which a conical rotor 

 uncovers a port in a conical seat. It operates without a stuffing box 

 and is designed so that the pressure of steam on the rotor is balanced, 

 reducing friction to a minimum. 



SCHEIDLER AND McNAMAR THROTTLE VALVE, 1875 



U.S.N.M. no. 3086S7 ; original patent model ; transferred from the United States 

 Patent OflSce; not illustrated. 



This model was submitted with the application for the patent 

 issued to Reinhard Scheidler and John H. McNamar, of Newark, 

 Ohio, June 8, 1875, no. 164219. 



The model represents a piston shaped regulating valve operated 

 by a lever, sector, and rack on the valve stem. It is designed for 

 use as an auxiliary valve in connection with a throttle valve of ordi- 

 nary form. The inventors describe the valve as being particularly 

 well fitted for the control of sawmill engines. 



HEWITT PISTON-ROD PACKING, 1879 

 Plate 21, Figure 2 



U.S.N.M. no. 309247; original patent model; transferred from the United States 

 Patent OflSce; photograph no. 32628A. 



This model was submitted with the application for the patent 

 issued to John Hewitt, of St. Louis, Mo., June 3, 1879, no. 216038. 



The model represents a 2-piece, flange-and-gland stuffing box of 

 the usual form, packed with malleable metal rings with beveled 

 edges. The rings are alternately beveled in opposite directions so 

 that adjoining surfaces match. The edges of the flange and gland are 

 beveled so that when the parts are brought together and tightened 

 the effect is of a number of double wedges sliding together and 

 expanding between the stuffing box and the shaft. 



CENTRIFUGAL SEPARATOR, c. 1879 

 U.S.N.M. no. 180924 ; original ; gift of the Deerfoot Farm Co. ; not Illustrated. 

 One of the earliest uses of the centrifugal separator for raising 

 cream from milk was at the Deerfoot Farm, Southborough, Mass. 

 The separator described here was one of the first three employed 

 there in 1879. It is included in this catalog because it is exhibited 

 in the Museum with the centrifugal oil separator, described below. 



