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Description of a Printing Chronograph. 



whole time for this adjustment need never exceed two 

 minutes. 



In the observation of zone stars, the type may be set to 

 give the integer seconds of mean right ascension, so that 

 the final reduction will always be a small quantity. 



The constant use of this mechanism on every day and 

 observing night, for more than five months, during which 

 time more than ten thousand records have been made, en- 

 ables us to speak with confidence of its success, both as 

 regards correctness in printing and in saving of labor. 



Other things being equal, it is found that for three ob- 

 servers, twice as many observations can be reduced in the 

 same time, as when a recording chronograph is employed. 



