Barometers Realm

This late-19th-century Pocket Self-Recording Barometric Altimeter by the renowned French manufacturer Jules Richard automatically records barometric pressure and the corresponding altitude over time onto a paper chart. The sophisticated barometric and clockwork mechanisms are housed in a compact case covered in fine morocco leather, fitted with a rectangular faceted glass viewing window. The instrument operates reliably in any position and weighs only 450 grams.

Jules Richard produced several variants of this instrument differing primarily in altitude range and drum rotation period (recording time). The example presented here is Model A, designed specifically for motorists. Its charts are graduated from 0 to 1200 meters, and it employs three aneroid capsules stacked in series to increase sensitivity. The recording drum completes one full revolution in six hours.

Other well-known versions (Models B and C) were intended for travelers, engineers, and aeronauts, and shared the same construction but featured different altitude scales: Model B: 0 to 2,400 meters and Model C: 0 to 5,000 meters. Depending on the model, the drum could rotate once every 6, 12, or 24 hours.

Each self-recording altimeter was supplied with a set of 50 replacement chart papers, a bottle of special ink, and a winding key. The instrument and accessories were housed in an elegant mahogany case with fitted compartments and a hinged, latched lid. The inside of the lid typically carried a detailed operating instruction sheet.

The Pocket Self-Recording Barometric Altimeter is remarkable both mechanically and aesthetically. Crafted with meticulous attention to detail, it continues to function flawlessly more than a century after its manufacture. One part of the instrument contains the twin rollers that hold and advance the chart paper; the other houses the integrated barometric and timing mechanisms, protected beneath a nickel-plated cover with the operating controls mounted on its surface.

Unlike conventional barographs, where the clock merely rotates the drum and the barometric mechanism moves the recording pen, here the two systems are mechanically interdependent. Every 15 seconds, a rectangular guiding frame lifts slightly, momentarily raising the recording pen and preventing ink blotting. This ingenious motion ensures a continuous, clean, and precise recording line across the chart.

In sum, this instrument stands as a miniature masterpiece of late-19th-century precision engineering — a portable scientific recorder that combines elegance, ingenuity, and enduring mechanical perfection.