Science – Radio-Guy

Rare 1862 Carlo Ponti Megalethoscope

steveanddan — Mon, 03 Aug 2026 15:05:40 +0000

This is a rare 1862 Carlo Ponti Megalethoscope. This is real survivor is amazing condition for its age. I found only one wooden trim piece missing on the underside.... It even has an original oil lamp on the back. We replaced the glass chimney. Over the years I have only seen an example like this once in a museum and in reference books. The decorative blacksmith iron rail that the housing sits on for rotating the camera is in the form of a snake. The main feature of this viewing device for photographs enlarges and adds apparent dimensionality to them. The photographs are applied to concave plates which are inserted into the viewer. The Megaletoscope was used to view photographs in two different ways with a light-dark effect. The observer viewed heavily enlarged pictures through the optical system. With the “daylight” view, the side shutters opened to allow daylight to illuminate the face of the photograph, a print on very fine albumin paper mounted with other elements on a wooden frame with handgrips. The body of the camera could turn through 90 degrees to enable the viewing of vertical pictures. With the “night-time” view, after re-closing the side shutters and opening the third shutter situated behind the camera in front of a light source, a coloured night-time scene appeared by transparency, with a totally different atmosphere. Some history... Carlo Ponti, born in Sagno in the canton of Ticino between 1822 and 1824, set himself up in Venice as an optician and photographer. From 1860, he perfected the “Aletoscopio” (from the Greek “true”, “exact” and “vision”), a viewing apparatus for large-sized photographs. In 1862, he put the finishing touches to the “Megaletoscopio”, an enlarged version of the Aletoscopio and entrusted its production to the cabinetmaker, Demetrio Puppolin. This example, in varnished walnut, the same size as a Megaletoscope despite its name, bears an oval ceramic plaque with the name C. Naya. If Carlo Ponti was actually given production exclusivity in 1862, the administrative confusion, which reigned the day after Venetia returned to Italy in October 1866, annulled this privilege and so other Venetian photographers, including Naya, were able to produce and sell this camera, which, by the way, cost the latter a lengthy lawsuit… 36" x 24.5" x 18.25"... $3600

Early 20th Century Anatomical Model of a Hen

steveanddan — Wed, 05 Nov 2025 19:38:55 +0000

This is an early life size size hand-painted paper mache and plaster anatomical model The paint and condition is very nice for something almost 100 years old. 18 inches tall x 16 inches wide... $1250

Knott – Induction Coil

steveanddan — Fri, 27 Jun 2025 18:41:10 +0000

E.I. Company – “Bull Dog” Spark Coil

steveanddan — Fri, 27 Jun 2025 18:11:15 +0000

Elektro-Vulkan Induction Coil

steveanddan — Fri, 27 Jun 2025 16:38:56 +0000

Welch Sample Tubes

steveanddan — Thu, 05 Jun 2025 15:07:22 +0000

American Plate Electrical Machine, ca. 1860

steveanddan — Wed, 30 Apr 2025 16:27:49 +0000

An elegant mid-19th century single-disc friction machine with turned hardwood pillars, brass fittings, and original clear glass plate—mounted on a classic cross-base with original aged patina. The green-painted collector shows flaking consistent with age, supported by a hand-blown glass pedestal insulator. While untested, the machine appears largely complete, retaining its original crank, rotating shaft, and collector arm. These early American electrostatic generators were used to demonstrate electrical charge and spark discharge in lecture halls and medical offices alike. A striking relic from the early days of electricity, ideal for display. $1400

Compact Wimshurst Influence Machine, Signed “MC”

steveanddan — Wed, 30 Apr 2025 16:19:44 +0000

A compact and visually striking Wimshurst electrostatic generator, likely late 19th to early 20th century, featuring dual contra-rotating disks with prominent radial foil sectors, twin Leyden jars, and brass discharge terminals. Signed simply "MC" at the base, this example is built on a cast metal platform and includes all major mechanical elements intact, though untested for functionality. The machine displays age-appropriate wear and patina, with oxidation to the foil and minor clouding in the glass capacitors—ideal for collectors of vintage physics apparatus and early electrical devices. ... $575

E. Thacher Cylindrical Slide Rule – With Original Case – Circa 1880s

steveanddan — Mon, 21 Apr 2025 14:48:12 +0000

A true monument to 19th-century engineering, this E. Thacher Cylindrical Slide Rule compresses over 40 feet of logarithmic scale into a beautifully machined rotating brass drum, designed for high-precision calculations long before the age of digital computing. Manufactured by Keuffel & Esser, this example shows its age with mellowed paper scales, gentle oxidation to the brass and steel framework, and a warm aged patina throughout. Still complete and solid, it comes housed in its original dovetailed hardwood case, scuffed and scratched as expected, but fully intact and functional. A classic piece of analog computing history, ready for display. $650

Tru-Sonic, Model OD-4 Oscillator and Demodulator

steveanddan — Tue, 15 Apr 2025 19:36:57 +0000

Stephens Manufacturing Corporation produced this Tru-Sonic, Model OD-4 Oscillator and Demodulator