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A physicist who translated Heinrich Hertz's Electric Waves into English for the 1893 edition.^[ref]

Identity: Trinity College archive identifies the translator as Daniel Evan Jones

By Heinrich Hertz.

Online text: archive.org/stream/b2172457x/b2172457x_djvu.txt

Collected experimental papers by Heinrich Hertz, in an authorized English translation by Daniel Evan Jones, published by Macmillan in 1893. The experiments and papers discussed here date to 1888. The archive link supplies OCR text; the apparatus illustrations are not reproduced.

Cited passages: Hertz, Electric Waves (1893 translation), VII, pp. 108–109; VIII, pp. 125–127; Hertz, Electric Waves, VII, pp. 107–108; Introduction, pp. 9–12: retrospective limitations; Hertz, Electric Waves, VIII, pp. 125–127 and 135–136: preparations and controls.

Homepage: www.dhm.de/lemo/biografie/heinrich-hertz

In his 1888 reflection experiments, Heinrich Hertz excited a straight conductor with a central spark gap driven by an induction coil. The receiver was a wire circle of $35\mathrm{cm}$ radius with an adjustable small spark gap; tiny sparks were observed in darkness. There was no connecting transmission wire. ^[ref]

He removed hanging metal fixtures, installed a $4\mathrm{m}$ by $2\mathrm{m}$ zinc reflecting sheet, and moved and rotated the receiver. Spark strength alternated with position and gap orientation, supporting specular reflection and wave interference. He checked observations from farther away because the observer's body perturbed the response. Changing oscillator dimensions changed the spatial pattern. ^[ref]

These tests supported propagating electromagnetic waves, rather than mere detection of nearby induction. They did not establish unlimited reception distance. His wire-versus-air wave interference experiment addressed finite velocity; he later judged its quantitative velocity comparison doubtful because of room effects. ^[ref]

The physical inference combines transmission with a spatially structured response to a reflected disturbance. In an ideal monochromatic incident-and-reflected model, standing wave nodes are separated by $\lambda /2$; combining a reliable wavelength with independently known frequency gives phase velocity $v=\nu \lambda$. A spark is a threshold event, however: its presence or length is not a calibrated wave intensity or a direct arrival-time measurement. The actual loop also responds to its orientation and finite size, so the simple standing-wave model is an explanation of the test's logic, rather than a reconstruction of Hertz's measured points. Poynting theorem explains how source energy can reach and drive the receiver's discharge.