Monthly Mean Relative Sunspot Numbers (1749-1976)

SUMMARY:
       Monthly means of daily relative sunspot numbers, which are
       based upon counts of spots and groups of spots.

SOURCE:
       D. F. Andrews and A. M. Herzberg, Data:  A  Collection  of
       Problems  from  Many  Fields  for the Student and Research
       Worker, Springer-Verlag, New York, 1985.

       The data was previously collected from different observers
       by   the  Swiss  Federal  Observatory,  Zurich,  Prof.  M.
       Waldmeier, Director.  M. Waldmeier, The  Sunspot  Activity
       in the Years 1610-1960, Schulthess, Zurich, 1961.

       The data is currently collected by the Tokyo  Astronomical
       Observatory, Tokyo, Japan. 

This data set is available in SPLUS.

Try it by typing

?sunspots	# produces the above message, I added the years
sunspots 
tsplot(sunspots)	# plot the series from 1749 to 1976, monthly data