particularly in terms of the variety of operations performed. 
.In spite of this, almost complete automation has been achieved 
on the IBM-709 Computer. By complete automation it is meant 
that only a single computer run is required for the entire re- 
duction--no intermediate data handling is necessary. A factor 
which contributes markedly to the efficiency of the present re- 
duction is the recording of the entire Boss Star Catalogue on 
high speed magnetic tape. Because of the star catalogue tapes, 
the formerly tedious and time consuming operations of identifying 
the selected reference stars and of compiling the catalogue data 
are now performed by the electronic computer. The computer makes 
far fewer misidentifications than a human, and can establish the 
identification of a total of 150 stars, consisting of 25 stars 
from each of six plates, in less than two minutes of computing 
and tape hunting. Indeed, on the 709 computer an entire six 
Station reduction, involving an average of 25 reference stars per 
plate and about 100 flash images, can be accomplished in a single 
computer run of less than one half hour. It is believed that 
this routine approaches the near ultimate in refinement and 
efficiency. 
The standard deviations currently attainable in measuring 
ballistic camera plates range from 2.5 to 3.5 microns, with 3 
microns being typical in a normal reduction. These figures re- 
Present the combined effect of setting error and emulsion insta- 
bility. The plate measuring accuracy can be converted into 
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