Barometers Realm

Biography and Work of Tremeschini

Joseph Antoine Tremeschini was a mid-19th-century engineer who worked in France. He lived in the commune of Le Lilas, near Paris, and gained recognition as an inventor of various scientific instruments. As early as 1844 and 1852, his developments received top awards at exhibitions, indicating his early recognition within the professional community. Initially, Tremeschini worked on timekeeping mechanisms and chronometric instruments: in 1863, he obtained a patent for a new gear system for machines and chronometers, and in 1867, he patented a “stellar meridian regulator” that allowed for the determination of both sidereal and mean time throughout the night. Later, he focused on astronomical and meteorological instruments, creating an educational cosmographic device in 1868 and publishing several scientific works, including studies on sunspots and auroras between 1869 and 1871.

By the early 1870s, Tremeschini had established his own enterprise as an ingénieur-constructeur—an independent engineer-constructor. His inventions attracted the attention of prominent colleagues; for example, in 1873, the renowned craftsman Louis Clément Breguet purchased Tremeschini’s telegraphic regulator for use on new railway lines. However, Tremeschini’s most notable achievements were in the improvement of meteorological instruments, particularly thermometers and specialized aneroid barometers, which he introduced in the 1870s. Between 1876 and 1878, he developed a highly sensitive metallic thermometer and an advanced aneroid barometer, establishing himself as an innovator in the field of meteorological instrument manufacturing. These developments solidified his reputation in scientific circles; he was a member of the French Meteorological Society and actively participated in discussions on the accuracy of atmospheric measurements during the rapid expansion of meteorology in the late 19th century.

Types of Barometers under the Tremeschini Name and Their Features

Tremeschini did not produce mercury barometers; instead, he specialized in liquid-free mechanical barometers—aneroids. Various aneroid barometers were released under his name, including pocket (portable) and wall-mounted models. The dial of these instruments often bore the Tremeschini logo, although he himself was not involved in their production, only in their design.

Tremeschini’s most famous invention was a barometer of his own design, featuring a radically simplified movement. This aneroid barometer eliminated several typical components, including the rack-and-pinion system, chain, and spiral spring. Additionally, Tremeschini employed an unusual mechanism to drive the indicator hand, a system also used in his metallic thermometer. In standard aneroids, small movements of the capsule walls are transmitted to the needle through a rack and sector gear (or a chain and helical spring), which complicates the mechanism and introduces friction.

In Tremeschini’s design, however, the sensitive aneroid chamber, containing an internal spring, transmitted its movement via a push rod soldered to the upper membrane. This push rod transferred movement to a primary lever, which in turn acted on an angular forked lever with a central shaft between its ends. A thin sliding bar was mounted on this shaft, and at its outer end, an unusual V-shaped steel element was fixed in a horizontal position (in traditional barometers, this position is occupied by a chain similar to a bicycle chain, wound around the shaft that rotates the indicator needle).

This V-shaped element was attached to the indicator shaft, which featured two worm gear threads into which the element engaged. The two diverging arms of this V-lever engaged with parallel helical grooves etched into the indicator shaft. At the slightest displacement of the capsule, the V-lever alternately contracted and expanded, forcing the shaft to rotate so that the arms remained aligned with the grooves. Thus, the linear motion of the capsule was directly converted into the rotation of the needle without intermediate gear transmissions.

This barometer was characterized by a simpler and more “direct” movement: the absence of unnecessary components was intended to reduce friction and inertia, thereby increasing the instrument’s sensitivity.

In addition to barometers, Tremeschini designed an original type of metallic thermometer (a monometric thermometer). This thermometer contained no liquid; instead, its sensing element was a thin metal strip (platinum-coated), which lengthened or shortened with temperature changes. The length fluctuations were recorded directly by the instrument, and due to the extremely low mass of the sensitive element, the thermometer was noted for its exceptional responsiveness and sensitivity. Contemporary observers remarked that this metallic thermometer instantly reached thermal equilibrium with the surrounding air and theoretically could surpass traditional mercury thermometers in measuring air temperature with greater accuracy.

Thus, under the Tremeschini name, both aneroid barometers (standard and improved designs) and new types of thermometers were produced, reflecting his inventive approach.

The Role of Other Manufacturers in Producing Tremeschini Barometers

Tremeschini did not own a factory for the mass production of barometers, so he commissioned their manufacture from leading French instrument makers of the time. Several firms were involved, each playing a specific role:

Dubois et Casse – One of the first Parisian firms to start industrial production of aneroid barometers after the expiration of Lucien Vidie’s patent monopoly in 1859. By the early 1860s, D&C had established the production of pocket and wall-mounted aneroids, becoming a key supplier of such mechanisms in France. It is likely that in the 1860s, Tremeschini ordered his custom-designed mechanisms from Dubois & Casse. This firm provided him with high-quality serial barometric mechanisms, which he could market under his own name.

Lion et Guichard – A Parisian firm that emerged around 1870 when Louis Guichard and Félix Lion acquired the barometer division from Breguet. Lion & Guichard positioned themselves as successors to Lucien Vidie, producing thousands of barometers in the 1870s. Tremeschini closely collaborated with Félix Lion Jr. in developing his improved aneroid. In 1877, they jointly filed a patent for a new barometer design, listing “Engineer Tremeschini” and “Félix Lion Jr., barometer manufacturer, both of Paris.” Lion & Guichard, with their manufacturing capabilities and expertise (inherited from Breguet), produced prototypes and possibly small production runs of Tremeschini’s barometers. Notably, the 1878 monometallic thermometer was manufactured at the Lion factory. Their collaboration allowed for the presentation of an improved aneroid barometer at an international exhibition, where it received an award (a silver medal was awarded to Guichard & Cie for barometers). Thus, Lion & Guichard played a crucial role in transforming Tremeschini’s inventions into actual products, handling assembly, calibration, and market promotion.

Clerget (and Soyer) – A Parisian workshop also involved in realizing Tremeschini’s projects, particularly in producing the prototype of the “rackless” aneroid. At the 1878 World Exposition, an aneroid barometer designed by Tremeschini was displayed, manufactured by “Messrs. Clerget and Soyer under the direction of Mr. Tremeschini.” This indicates that Clerget & Soyer were responsible for implementing Tremeschini’s barometric system without a rack, chain, or spiral spring. By 1878, cooperation with Lion & Guichard may have ended or become insufficient, leading Tremeschini to enlist Clerget for the assembly of his innovative instrument. This company provided the delicate mechanical work, including the precision engraving of screw threads on the indicator shaft and fine-tuning of the V-lever. The result was a functional exhibit, showcased to the public.

Overall, these manufacturers enabled Tremeschini, as an inventor and engineer, to turn his ideas into tangible instruments.

Surviving Examples of Tremeschini Barometers

Original Tremeschini instruments are rare today, but some specimens have survived in museums and private collections. In 1880, immediately after the Paris Exhibition, an aneroid barometer and a metallic thermometer of the Tremeschini system were acquired for the French National Collection of Scientific Instruments.

A stellar clock (horloge stellaire) by Tremeschini has been documented in a private collection and was offered on the antique market in the 2010s for approximately $4,500, reflecting its historical significance.

Regarding aneroid barometers bearing the Tremeschini name, they are of considerable interest to collectors of Victorian-era instruments. Since the inventor produced only a limited number of these devices—most being experimental models or small production runs—each surviving specimen is regarded as a rarity. While Tremeschini’s name is not as widely recognized as Torricelli or Vidie, among enthusiasts of scientific antiques, it remains associated with innovation and quality.