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INDEX OF CATEGORIES

ELECTRICITY
1 CYLINDRICAL CONDUCTOR WITH ELECTRIC PENDULUMS
2 ELECTRIC CARILLON
3 CAVENDISH-BECCARIA ELECTRIC HOLLOW GLOBE
4 LIGHTNING-CONDUCTORS
5 LEYDEN JARS
6 BATTERY OF NINE LEYDEN JARS
7 LUMINOUS LEYDEN JAR
8 LANE'S MICROMETRICAL SPARK GAP WITH LEYDEN JAR
9 FRANKLIN'S BATTERY
10 EPINOUS'S CONDENSER
11 DISCHARGER
12 DISCHARGER
13 ELECTROSTATIC DISCHARGER WITH DOUBLE FORK
14 MASCART'S INSULATORS
15 VOLTA'S PISTOL
16 VOLTA'S PISTOL (2 PIECES)
17 PITH-BALL AND GOLD LEAF ELECTROSCOPES
18 BOHNENBERGER'S ELECTROSCOPE
19 BOHNENBERGER'S ELECTROSCOPE
20 PELTIER'S ATMOSPHERIC ELECTROMETER
21 PELTIER'S ATMOSPHERIC ELECTROMETER
22 HENLY'S ELECTROMETER
23 ELECTROSTATIC BALANCE
24 THOMSON-MASCART'S QUADRANT ELECTROMETER
25 WINTER'S PLATE ELECTRICAL MACHINE
26 ACCESSORIES OF THE WINTER'S MACHINE
27 SPIRAL FULMINATING TUBE
28 HOLTZ'S ELECTROSTATIC INFLUENCE MACHINE
29 ELECTROSTATIC MACHINE WITH SELF-EXCITATION TOPLER-VOSS
30 POTASSIUM BICHROMATE ELECTROCHEMICAL CELLS
31 NOBILI'S PORTABLE GALVANOMETER
32 ASTATIC GALVANOMETER
33 MELLONI'S THERMOMULTIPLIER
34 UNIVERSAL MEASURING DEVICE, MOVING COIL TYPE
35 AMPERE'S APPARATUS
36 MAGNETIC SPARKLER
37 INSTRUMENTS OF NOBILI'S "ELECTROMAGNETIC BOX"
38 BARLOW'S WHEEL [1]
39 SMALL CONTAINER WITH TWO VERTICAL WIRES [2]
40 SMALL CONTAINER WITH TWO HORIZONTAL WIRES [3]
41 FARADAY'S DEVICE FOR THE CONTINUOUS CIRCUIT [4]
42 DEVICE FOR SHOWING THE DIRECTIVE ACTION OF THE EARTH'S MAGNETIC FIELD ON VERTICAL CURRENTS
43 DEVICE FOR SHOWING THE CONTINUOUS ROTATION OF A MOVING CIRCUIT BY MEANS OF A FIXED CIRCULAR CURRENT
44 MATTEUCCI'S SPIRAL PLATES INDUCTION DEVICE
45 LITTLE MEDICAL INDUCTION COIL WITH MANUAL CONTACT-BREAKER (WHEEL TYPE)
46 LITTLE MEDICAL INDUCTION COIL WITH HAMMER-BREAKER (HORSESHOE-SHAPED ELECTROMAGNET TYPE)
47 INDUCTION COIL
48 INDUCTION COIL WITH PLATINUM AND MERCURY CONTACT-BREAKERS
49 INDUCTION COIL WITH SPARK GAP AND FOUCAULT CONTACT-BREAKER
50 INDUCTION COIL
51 DE LA RIVE INDUCTION COIL
52 BOURBOUZE'S ELECTROMOTOR
53 CLARKE'S MAGNETO-ELECTRIC MACHINE
54 MAGNETO-ELECTRIC MACHINE FOR ELECTROTHERAPY
55 VOLTAIC ARC WITH MANUAL ADJUSTMENT
56 ELECTRIC EGG
57 DE LA RIVE'S ELECTRIC EGG
58 GENERAL VIEW OF THE EDUCATIONAL STRUCTURE WITH DEVICES FOR ELECTRICAL ENERGY CONTROL AND DISTRIBUTION
59 RIGHI'S THREE SPARKS OSCILLATOR
60 COUPLE OF TRANSMITTER AND RECEIVER TELEPHONES WITH WHISTLE CALLING
61 FOUR TELEPHONES BELL-TYPE
62 TWO TELEPHONES BELL-TYPE
63 RIGHI'S TELEPHONE RECEIVER
64 RIGHI'S MICROPHONE
65 PNEUMATIC TELEGRAPHS (DIAL TYPE)
66 SKINWIRE FOR TELEGRAPHIC LINES
67 MORSE'S RECORDING TELEGRAPH WITH KEY

OUR COLLECTION OF SCIENTIFIC INSTRUMENTS

ELECTRICITY




Mascart's insulators Isolatori di Mascart
Subjects: electrostatics/charged body insulators Settore: elettrostatica/isolatori di corpi carichi
Inventory Number: 297 - 318 Numero di inventario: 297 - 318
Unsigned Non firmati
2/2 of the 19th century Periodo di costruzione: 2/2 del XIX secolo
Glass, brass, sulphuric acid Materiali utilizzati: Vetro, ottone, acido solforico
Ø: 135, 140 [mm]; heights: 280, 300 [mm] Dimensioni: Ø: 135, 140 [mm]; altezze: 280, 300 [mm]
   
This pair of electrostatic insulators was designed by the French physicist Eleuthère Mascart (1837-1908). They permit the preservation of a charge for a long period of time without leakage. An electrified object loses its charge if it is not very well insulated. In order to avoid deposits of humidity Mascart improvemed the insulating capacity of the glass base by using concentrated sulphuric acid instead of paints having low hygroscopic capacity, such as shellac.
Questa coppia di isolatori elettrostatici, ideati dal fisico francese Eleuthère Mascart (1837-1908), permette di mantenere senza dispersione una carica elettrica per lungo tempo. Un corpo elettrizzato, se non è ben isolato dal suolo, perde per dispersione la sua carica. Contro i depositi d'umidità, Mascart propose di migliorare la capacità isolante del supporto in vetro anzichè di ricorrere a vernici di piccola capacità igroscopica (quali ad esempio la gommalacca) facendo uso di acido solforico concentrato.
   
Description: The insulators are identical in shape but they differ in the varying forms of the upper metal conductors. The insulating part consists of a glass container, the bottom of which bends down to form a sort of tube that extends until it comes out from the container's mouth and is then enclosed in a brass cylinder. By applying pressure, metal conductors of different shapes may be inserted on the brass cylinder to support and to keep electrified objects insulated. A concentrated solution of sulphuric acid on the bottom of the glass container keeps the glass constantly dry due to the absorption of humidity.
Descrizione: gli isolatori, identici nella forma, si distinguono per la diversa forma dei conduttori metallici superiori. La parte isolante è costituita da un recipiente in vetro il cui fondo si ripiega verso l'interno in una specie di tubo che si prolunga fino ad uscire dall'imboccatura del recipiente stesso per incastrarsi in un cilindro d'ottone. Su di esso si possono inserire a pressione conduttori metallici di varie forme per sostenere e mantenere ben isolati oggetti carichi elettricamente. Il fondo del recipiente di vetro contiene una soluzione concentrata di acido solforico che, assorbendo l'umidità, mantiene costantemente secco e ben asciutto il vetro.
   
Bibliography: Mascart [1878], vol.VII, p. 217; Pellat [1901], tome I, pp. 7-8.

Bibliografia: Mascart [1878], Vol. VII, p. 217; Pellat [1901], tome I, pp. 7-8

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