CATALOG OF THE MECHANICAL COLLECTIONS 17 



stationary apron fitting as closely as practicable to the circumference. 

 The best of these wheels was about 75 percent efficient. One installa- 

 tion, that of the Merrimac Co., consisted of eight wheels, each 30 

 feet in diameter and 12 feet wide. Until 1840 this type of wheel was 

 j)ractically the only one used and may be said to have reached the 

 period of its greatest application then. Subsequent to 1840 the 

 hydraulic turbine began to replace the water w^heel in the American 

 mills. 



Hydraulic turbines in the United States. — Accounts tell of the use 

 of a hydraulic turbine in Massachusetts as early as 1790, though with 

 no practical or permanent success. The continuous development of 

 the turbine in the United States begins about 1843, when the work 

 of Fourneyron in France was made known to engineers by a series 

 of tests of turbines of the Fourneyron type conducted by Ellwood 

 Morris, engineer, at Philadelphia. His results indicated that a maxi- 

 mum efficiency of 75 percent, equal to that of the best water wheels 

 in use, was possible with the turbine. The natural advantages of the 

 turbine over the water wheel then caused mill owners to consider its 

 use. In the same year George Kilburn, of New Hampshire, built and 

 installed the first turbine to be used practically in New England at 

 the print works of Robeson & Sons, Fall River, Mass. In 1844 Uriah 

 Boyden designed a turbine of 75 horsepower for the Appleton Co. 

 at Lowell, and two years later three more of 190 horsepower each for 

 the same company. "These wheels were of the Fourneyron type with 

 certain improvements effected by Boyden, including diff users (Pat- 

 ent no. 5090) and other peculiar devices." An efficiency of 88 per- 

 cent was claimed for the early Boyden-Fourneyron turbines, which 

 led to the installation of turbines in every new mill in New England 

 and in the old mills as rapidly as the water wheels wore out. In the 

 meantime a purely American development in turbines was taking 

 place in the perfection of the inward-flow and mixed-flow turbines. 

 Jonval of France suggested the inward-flow turbine in 1829, but the 

 first of the type was built by Samuel B. Howd, of Geneva, N. Y., who 

 obtained a patent in 1838 (Patent no. 861). The runner of the Howd 

 turbine was made of a ring of shallow curved buckets around the 

 periphery of a light wheel. The sides of the buckets were vertical, 

 and the water flowing through the buckets radially toward the 

 center was confined to a horizontal path until it left the inner rim of 

 the wheel, when it began to fall, running off parallel to the vertical 

 shaft. The water was directed into the runner by straight stationary 

 guide vanes. The Howd turbine was simple and cheap, and many 

 were installed in small mills where they gave the advantages of the 

 turbine at small initial cost. About 1849 James B. Francis designed 

 an inward-flow turbine under the Howd patent in which the vanes 

 were shaped to deflect the water downward before it left the vanes 



