File:SB-07-136-source-2.png

Summary

Description

Fig. 2: velocity–time rectangle ABCD with diagonal, from The Spiritualist, vol. XII, no. 21 (whole no. 300), 24 May 1878, printed p. 250 (PDF page 12 of 16). Part of Desmond G. Fitzgerald's article The “Conservation of Energy” in Relation to Certain Views of the Theosophists, beginning on printed p. 249. The author is credited for the article, not assigned as illustrator or engraver.

Matches item 3 on HPB-SB-7-136. Rectangle vertices A/B/C/D, diagonal BC, time marks1–4, central fraction and printed Fig.2 caption match item3. Item2 is a displayed formula, not this figure. The whole diagram, labels and original printed figure caption are retained. There are two actual numbered figures on the journal page; the album's other image-labelled items on this page are displayed formulas, not nine additional engravings. This file does not alter the album text or mathematical transcription. No historical artist or engraver is identified from the page.

Source

International Association for the Preservation of Spiritualist and Occult Periodicals (IAPSOP), exact issue listed in its Spiritualist archive index, checked 5 November 2026. Complete source PDF, printed p. 250 / PDF page 12. The issue header and article opening on p. 249 were visually checked.

A different PDF of the same issue is already held in Teopedia as File:London spiritualist n.300 1878-05-24.pdf. It is not the byte-identical source of this crop; no existing file was overwritten or reuploaded. The exact IAPSOP PDF used here is 3,101,104 bytes, SHA-256 7da57ee5bad0db0500ed43e9e208c04c4db1586271033ad1d9fee0b5e62fa429.

Thank you to IAPSOP for preserving this periodical and freely providing the scan and catalogue.

Rights

The nineteenth-century diagram is public domain by age. The current IAPSOP index states that its materials are provided under Creative Commons Attribution–NonCommercial 4.0 International. Credit: IAPSOP. This crop/deskew is identified as an adaptation; the noncommercial condition is retained. No CC0 or institutional Public Domain Mark is claimed.

File and processing

Lossless RGB PNG, 545 × 245 pixels, reproducing a black-and-white source scan. The PDF page was composed at its native 2684 × 4005 page grid, including the whole-page one-bit JBIG2 image inside the foreground Form and the separate 497 × 227 one-bit image patch inside another Form. No layer or patch was omitted, and no enlargement was applied.

One 0.135592346° counterclockwise BICUBIC rotation on the full canvas without expansion; crop (1685, 1015)–(2230, 1260), right/bottom exclusive. Page tilt measured on the long inter-column rule (202 inliers), independently corroborated by Fig.2's horizontal top (210 samples, 0.116812935°). The drawn rope's own slight inclination was not forced upright. Exact independent pixel replay and full source-supported crop checked. No tonal adjustment, sharpening, retouching, reconstructed lines or colourization; natural paper colour is absent from this digital source.