This source belongs in the archive because it records Steinmetz speaking directly about relativity, space, gravitation, and field geometry late in his life. It should be handled with unusual care: it is not a license to project later ether-field interpretations backward into his electrical books.
This book may become important for ether, space, and field comparison pages, but only after passages are quoted and located exactly. Modern physics explanations and ether-field readings must remain separate layers.
Research metadata: dashboards, counts, and verification routes
Generated source dashboard: this section joins the source overview to the book coverage atlas, source text reader, chapter workbench, visual maps, and formula maps. Counts are candidate research aids until scan verification promotes them.
Four Lectures on Relativity and Space currently contributes 4 processed sections and 39,381 candidate OCR/PDF-text words to the archive. Its strongest tracked evidence clusters are Field language, Radiation / light, Waves / transmission lines.
This is a routing judgment based on processed metadata, not a final historical claim. The strongest next move for any exact quotation, equation, or diagram is still to open the source scan and check the page image.