696 SEC. 14. METEOROLOGY. 



be on an adjacent hill or tower), it may be connected electrically with a dial or 

 with a self-recording apparatus. 



In such a case, the dial above described should be read periodically as a 

 check 011 the electrical dial. 



To adopt the length of the shaft to the circumstances of various stations, 

 the shafting is supplied in lengths of four feet, with one of two feet, one of 

 one foot, and one telescopic piece. 



2845b. Windmill Vane with electrical arrangement 



whereby the direction of the wind at any instant may be known 

 by sound, constructed for stations of the second and third order 

 in connection with the Meteorological Office of the Dominion of 

 Canada. G.T. Kingston, M.A., Toronto, Canada. 



This instrument is designed to meet the case when a vane, if suitably 

 exposed, is too distant to admit of being connected by a shaft with a dial in 

 an accessible position. 



Surrounding the step of the vane and attached to the bottom of the box i* 

 a fiat brass ring divided by radial lines into four equal parts corresponding to, 

 but not necessarily in the direction of the four cardinal points, and separated 

 by small equal intervals. 



The direction arcs (as they may be termed) are insulated, except as regard? 

 connection with their screw cups. 



Clamped to the spindle, and capable of adjustment in azimuth, is a circuit 

 maker, which consists of an arm bearing a brass arc, which is made to press 

 on the flat brass ring. The length of this arc is 45 + interval between the 

 fixed arcs. The" step of the vane is connected by wire with one pole of a 

 battery, and the direction arcs with four screw cups in near proximity to a 

 brass plate fastened to the wall of the office, and so contrived that, by aid of 

 a plug, metallic connection may be made at will between the brass plate and 

 any one of the four wires. 



Finally, two wires from the poles of a small telegraph sounder are attached 

 to the brass plate and to the other pole of the battery, and the apparatus is 

 complete. 



To ascertain the direction of the wind, notice \>y the sounder which direction 

 arcs or pair of arcs is placed in circuit as the brass plate is connected by the 

 plug with the four wires in succession. 



If, for instance, N. only sounds, the direction is nearer to N. than either 

 to N.W. or N.E., unless it be N.N.W. or N.N.E. exactly, but if N. and E. both 

 sound the direction is nearer to N.E. than either to N. or E., unless it be 

 N.N.E. or E.N.E. exactly. 



The azimuth of the vane box need be governed only by appearance and the 

 position of the door. 



To adjust the vane, unclamp the circuit maker, and insert a pin (provided 

 for the purpose) through holes at the middle point of the circuit maker and 

 the arc at the left of the box, which arc may represent any one of the four 

 cardinal points. Turn the vane to that point, clamp the circuit maker, 

 and remove the pin, when the adjustment will be complete. 



The apparatus works well with a single gravity cell, when the vane is 60 

 feet or more from the battery and sounder. With a stronger battery it works 

 well at the distance of a mile or more. 



3388a. Signer Bianchi's Air Meter. 



Conservatoire des Arts et Metiers, Paris. 



