VII. RECORDING INSTRUMENTS. ,585 



2873. Self-recording Barometer and Thermometer for 



use on board ships. 



Dr. Franz Paugger, Director of the I. R. Commercial and 

 Nautical Academy at Trieste. 



This apparatus, which is enclosed in a small box, consists of three principal 

 parts : 



A thermometer, a barometer, and a contrivance for registering. 



The thermometer is composed of a system of 10 zinc tubes, one foot 

 English in length, which are placed side by side in the form of a cylinder, 

 each one of which, commencing from the first, transmits, by means of a lever, 

 to the next tube, in a somewhat augmented degree, its linear expansion 

 produced by increase of heat. This system of tubes is suspended in the open 

 air and surrounded by a shell or cover in the form of Venetian blinds at the 

 back of the parallel tubular box. From the end of the last tube a somewhat 

 longer lever extends into the interior of the box, as far as the writing cylinder, 

 by which the variation of the temperature, caused by the total expansion or 

 contraction of the tubular system, is automatically recorded from time to time. 

 The motor for the measurement of the atmospheric pressure is composed 

 of 10 aneroid cases, which are joined ^together in the shape of a column. 

 Their expansion or contraction, produced by the changes in the atmospheric 

 pressure, is transmitted to the writing cylinder by means of a lever. 



The arrangement for registering consists of a cylinder placed vertically, 

 which is turned on its axis every 24 hours by a clock movement in the front part 

 f the box. The two levers, both extending horizontally from the thermometer 

 and the barometer, as far as the same edge of the cylinder, are at a mean tem- 

 perature and a mean atmospheric pressure in a position the one in the centre of 

 the lower, and the other in the centre of the upper half of the writing 

 cylinder. Every 15 minutes, the ends of the levers, which are provided with 

 pencils, are pressed against the cylinder, and by these means the variations of 

 the atmospheric pressure and of the temperature are regularly registered. 

 The instrument is in all its parts so contrived as not to require a fixed 

 position, and being easily transportable, it can be used without difficulty on 

 board ship. 



2873a. Self-registering and Signalling Vessel Baro- 

 meter. Dr. Fricdr. Muller, C.G., Osnabruck. 



This self-registering and sign ailing barometer is new, both as a whole, and 

 in its details. The points of novelty are : 



I. The bulb barometer, which is entirely independent of the registering and 

 signalling mechanism, and which possesses the following properties: (a.)The 

 reading takes place at the lower level by unchanged position of the upper. 

 (6.) The galvanoscopic adjustments, accomplished by means of the platinum 

 point fused into the Torricellian vacuum, requires no sight, is very simple, 

 quickly performed, and free from errors. (e.) The construction of the 

 cistern with the barometric tube passing through it, whereby the level of 

 mercury in the cistern is kept invariable, (d.) No boiling of the tube is 

 required, (e.) By the introduction of a small quantity of dry hydrogen 

 into the vacuum, the influences of temperature may easily* be compensated. 



II. The uninterrupted automatic adjustment, which makes all changes in 

 the atmospheric pressure, even the smallest oscillations, audible. Specially 

 deserving of attention are: (a.) The two platinum points in connexion with 

 (&.) the two sliding relays, working [in opposite directions, and (c.) the two 

 little electro-motor machines, which by their beats give direct indication of 



