From the beginning, the number of observations being sent to the AAVSO each year began to rise dramatically: from 4,900 in 1911; to 11,600 in 1912; 16,800 in 1914; 17,400 in 1917; 19,300 in 1921; and 26,900 in 1924.
Amateur observers of variable stars in the United States from 1875 to 1910. The full text of this article appears in the Journal of the AAVSO, Vol. 27, No. 2, 1999.
