The graph shows the writing activity of the century's tidal scientists. The scientists formed three distinct networks: the early, synthetic network; the later, harmonic network; and the network formed in America. The very first bump in the 1820's is the last effort of gold-diggers applying to the residual Board of Longitude. Then Lubbock's receipts caused the first and largest peak, followed immediately by peaks instigated by Whewell. They sustained their combined effort throughout the 30's, merging into the work of Airy which dominated the 40's. The ill-fated Fairy experiment caused the singular peak of the late 40's.

    The main peaks of the 50's are activity in America. Further activity in America, for the remainder of the century, is absent from the graph owing to my lack of continued research in the National Archives, Washington.

    The rise toward the end of the 70's is owing to Thomson, and the dramatic rise to the second highest peak to Darwin, who had completed his tidal work by the century's end. The public row between Thomson and Roberts at the end of the 1870's shows clearly.