Two guide sheets for George Darwin's tidal abacus, 1892. Guidesheets for George Darwin's Tidal Abacus, 1892 1892
Complete set of computation sheets for analysis of results obtained with George Darwin's tidal abacus, 1892. Inv. No. 1925-947 Computation Sheets for George Darwin's Tidal Abacus, 1892 1892
Two computation sheets, for George Darwin's tidal abacus, 1892. Computation Sheets for George Darwin's Tidal Abacus, 1892 1892