52 A MANUAL FOB NORTHERN WOODSMEN 



REFLECTOR 



Zeta 



ing as dark lines. If light enough is not so obtained, 

 a tin reflector may be made of the design shown, or a 

 piece of tracing cloth or greased paper 

 with a hole cut in it may be bound bell- 

 shape over the front of the instrument 

 with a string or rubber band. 



Directions for obtaining the true merid- 

 ian which involve an accurate knowledge 

 of time are not adapted to the use of the 

 woodsman. The following directions do 

 not impose that very difficult requirement. 

 (From United States " Manual of Instructions for Sur- 

 vey of the Public Lands.") 



To OBTAIN A MERIDIAN AT CULMINATION OF POLARIS 



A very close approximation to a meridian may be had by re- 

 membering that Polaris very nearly reaches the meridian when 

 it is in the same vertical plane with the star Delta (5) in the con- 

 stellation Cassiopeia. The vertical 

 wire of the transit should be fixed 

 upon Polaris, and occasionally brought 

 down to the star Delta, to observe its 

 approach to the same vertical line. * 

 When both stars are seen upon the 

 wire, Polaris is very near the meridian. 

 A small interval of time (as 6 min. in 

 1908) will then be allowed to pass, 

 while Delta moves rapidly east and 

 Polaris slightly east to the actual me- 

 ridian. At that moment the cross wire 

 should be placed upon Polaris, and the 

 meridian firmly marked by stakes and 

 tack-heads. 



This method is practicable only 

 when the star Delta is below the pole 

 during the night; when it passes the 

 meridian above the pole, it is too near 

 the zenith to be of service, in which 

 case the star Zeta (f), the last star but 

 one in the tail of the Great Bear, may 

 be used instead. 



^ Delta (5) Cassiopeia; is on the me- 

 ridian below Polaris and the pole, at Cassio 

 midnight utxiut April 10, and is, there- 

 fore, the proper star to use at that date and for some two or! 

 three months before and after. 



Great 



Polaris 



Delta 



North Pole 



pela 



