Pages Navigation Menu

A BAROGRAPH

Number in the past inventory 2892

Number in the current inventory 81

INSTRUMENT: A BAROGRAPH

Age: beginning of the twentieth century

Creator: P.G. Garofalo Ottici, Palermo, Italy

Materials: Wood, paper, mercury, glass, brass, ivory

Size: (146 x 290 x 177) mm

State of conservation: Good

Information: From the information contained in the old inventory register, found in the school, the instrument is said to have been added to the inventory with the number 2892 on 28th May 1942 priced at 6,750 liras.

Description: The instrument is kept in a wood box with glass side walls, with a brass handle and a label where it is written: “Barometro olosterico di precisione P.G.Garofalo Ottici Palermo”
The holosteric barograph consists of a round metal box with a flexible and corrugated cover. The box is empty. The instrument is made up of a holosteric baromether made of a lot of metal small boxes, one on top of the other. The system is connected by a lever to an index which ends with a pen resting on a piece of paper rolled on a metal cylinder. Inside the cylinder there is a clockwork movement which makes the cylinder spin. The column of the little boxes is connected by a rod to a metal sheet folded upon itself and connected by a system of levers to an indicating pointer. Next to the cylinder there is a thermometer graduated in Celsius and Reaumur. On the index support there is written “Barometre holosterique”. The number 228 and a circle with the letters H B N P placed crosswise are engraved on the inside base of the box covered with brass. A corrugated paper box containing strips of recording paper to roll up on the cylinder is part of the kit of this instrument.

Use: The box changes its shape because of the pressure variations and the movement is transmitted to the pen which records the pressure gait. There is a paper strip for each day of the week and each one has a pressure scale, so you can study the atmospheric pressure gait of a specific place when the weather changes.

Leave a Comment

Your email address will not be published. Required fields are marked *