Click on the thumbnail at the bottom right of this page to go to the bitmap scan of this document. The text of this document appears immediately below.
AURORA Bulletin No, 2 (cont'd.) a small area of the sky (such as those who can not see the northern sky) can report on those parts of the sky that they can see and which are free of aurora. These casual and partial reports can later be pieced together by the local recorder and often the Centre will thereby be able to report "no aurora in clear sky" from a composite of several of these negative views of the incomplete sky. THE N.R.C. SURVEY OF AURORA For information regarding observation of the aurora in co-operation with the National Research Council's Auroral Survey, write to:- Auroral Centre, National Research Council, Ottawa 2, Ontario, A supply of report forms, mailing envelopes and instructions is available on request. The value of all positive observations of aurora can not be over-estimated, but it must be remembered that negative ob…ervations are also very useful in the N.R.C. auroral survey. To be most useful, negative observations should be made between five minutes prior to the hour and five minutes after the hour. Made within this ten minute interRal the data are easiest to handle in the N.R.C. data system, but reports of "sky clear, no aurora" are valuable regardless of what time they are made. Negative observations can be made with cloud cover approaching 40% of the sky, especially when the northern sky or the north-south meridian is free from cloud. The reporting of the presence, or absence, of aurora in the sky is important, so keep looking! Since the study of aurora is often interfered with by cloud cover, even occas- ional reports made when the sky is clear and when it is convenient for the observer to make out a report can serve as very useful data. A regular observer may be clouded aut and unable to report on the very night when you CAN observe. It may be YOUR report that fills the gap. So keep looking! And remember that "Nothing is as good as Something so far as aurora is concerned". I would be pleased to discuss methods of supplementing the N R C observing programme for use in your local Centre. I have a very small supply of types of report forms already in use for both negative and positive reporting programmes as well as information concerning how to use observing data to make conclusions regard- ing location and frequency of auroral displays. I shall be pleased to hear from your group. Thanking you for your co-operation, I am, your National Co-ordinator NOTE: Earl Milton Present Address Apt. 17, 729 Cooper Street, Ottawa 4, Ontario.