■^^ BULLETIN 173, U. S. NATIONAL MUSEUM 



ADDITIONAL WINDMILLS IN THE COLLECTION, NOT DESCRIBED 



Windmill, Patent Office model, Patent no. 208208, issued to Elijah H. Smith, 

 September 17, 1S78. U.S.N.M. no. 309137. 



Windniil], Patent Office model. Patent no. 209583, issued to Jesse Benson, 

 November 12, 1878. U.S.N.M. no. 309133. 



Wind engine, Patent Office model, Patent no. 209862, issued to John Cook, 

 November 12, 1878. U.S.N.M. no. 309135. 



Windmill, Patent Office model. Patent no. 222340, issued to H. M. Wood. 

 December 2, 1879. U.S.N.M. no. 309136. 



WATER POWER 



Water wheels. — Flowing and falling water was utilized to drive 

 simple machines many centuries ago. The noria, a wheel turned by 

 the current of a stream and employed to raise water from the stream 

 by means of jars attached to the rim of the wheel, was the earliest 

 water-powered machine and probably the first machine to be driven 

 by any power other than the muscular power of men and beasts. 

 The first water wheel in history is one discussed by Philo of Byzan- 

 tium, a Greek writer of the second or third century B. C. He ap- 

 parently described a then existing water wheel driving a chain of 

 buckets for raising water. The first mention of a particular water 

 wheel was given by Strabo (63 B. C.-21 A. D.) of a water mill set 

 up in Asia Minor in 88 B. C. for Mithridates VI, king of Pontus. 

 This is also the first mention of a water mill. It is assumed that 

 this first mill was of the simplest type, consisting of a vertical shaft 

 of wood with a horizontal wheel formed of a series of warped wooden 

 blades at its lower end with a horizontal rotary millstone attached 

 to the upper end. Falling water was directed onto the blades of the 

 wheel in a direction parallel to the vertical shaft. This type of mill 

 has been definitely identified in the fifth century and was in general 

 use throughout Europe in the Middle Ages. It has become known 

 as the Greek or Norse mill in distinction from the Roman mill, which 

 was first suggested by Vitruvius (first century B. C.) about 16 B. C. 

 In the Roman mill the vertical shaft of the millstone was connected 

 by gearing to the horizontal shaft of a vertical current wheel, essen- 

 tially as in the mills with undershot wheels of recent date. There is 

 no evidence of the use of this type of mill before the fourth century, 

 and it was not in general use much before the twelfth century. As 

 indicated before, the first vertical water wheel was the current wheel, 

 a large wooden wheel with boardlike vanes or paddles attached 

 radially to the wheel with the surface of each paddle in a plane 

 through the axle of the wheel. The wheel was so mounted that the 

 paddles dipped into the stream and presented their broad surfaces 

 to the flow of the current, which forced the wheel around. The un- 

 confined current headed up against the paddles and escaped past 



