256 proceedings: anthropological society 



Whence d = —. 



Now selecting the customary unit — miles per hour — and letting t 



be one minute for convenience, we have: 



1 X 5280 

 d = — = 88 feet, which must be the travel between contacts 



6!) 



in order that the number of contacts per minute shall be equal to the 



velocity in miles per hour. 



dT 

 We may now write i = -jr- 



We have, therefore, the following rule for the use of the instrument, 

 the same consti'uction answering for any unit of measurement desired: 



"The number of signals in 60 seconds equals the velocity of the wind 

 in statute miles per hour. 



The number of signals in 52 seconds equals the velocity of the wind 

 in knots per hour. 



The number of signals in 27 seconds equals the velocity of the wind 

 in metres per second. 



The number of signals in 97 seconds equals the velocity of the wind 

 in kilometers per hour." 



It is evident that the customary dial mechanism may be omitted 

 from the instrument entirely, thus eliminating tedious and expensive 

 construction work and lessening the cost. The standard cups, spindle, 

 and bearings have been retained in order to preserve the present relation 

 between wind movement and cup movement; but the framework of 

 the instrument has been made of materials easily available to manu- 

 facturers, instead of the tapered tul^ing used in the old pattern, which 

 requires special orders through the mills for its production. 



Gustiness of the wind is indicated in a general way by the variation 

 in the frequency of signal, and the anemometer thus gives information 

 that is lacking in the ordinary one-mile registration. 



A similar device has been manufactured by Richard, Paris, for many 

 years, but the contacts are made to actuate a pen arm upon a sheet to 

 produce a continuous record. Mr. Friez, of Baltimore, has marketed 

 an anemometer that makes contact every 3^ mile, but it required a 

 table for interpretation of the signals. 



The price of the new model is not yet definitely known, but should 

 not exceed $25 for a complete equipment, as compared with $100 

 for standard anemometer and register. 



Discussion: This paper was discussed by Messrs. Burgess, Schlink, 

 Herschel, Humphreys, and Briggs. 



H. L. Curtis, Recording Secretary. 



ANTHROPOLOGICAL SOCIETY OF WASHINGTON 



The 523rd meeting of the Society was held in the West Study Room 

 of the Public Library on Tuesday evening, March 12, 1918, at 8 p.m. 

 The speaker of the evening was Mr. Edward T. Williams, Chief 



