The electric lightbulb replaced previously used light sources that were based on burning fuels in different states of matter (candles, kerosene or gas lamps). Electric light sources proved to be more convenient in everyday use, which drove the enormous commercial success of the lightbulb and its ubiquity in private homes and public spaces. Each lightbulb consists of a filament (i.e., a thread glowing under the influence of electricity flowing through it), a base connected to the power source, and a glass bulb that ensures the appropriate environment for the filament inside to work. The patent for the lightbulb belonged to the American inventor and entrepreneur Thomas Alva Edison.
The item presented here was produced in Vertex Elektrowerke in Germany, from 1921 a part of the Osram group, the manufacturer of different types of electric light sources. The Osram name, established in 1906, is a combination of parts of the name of elements used for the production of filaments: osmium and wolfram (Eng. tungsten). From 1922, a branch of the German group was in operation in Poland under the name ‘Polska Żarówka „Osram”’.
Interesting fact: Incandescent lightbulbs are falling out of use as the main source of light in households due to their low efficiency in comparison with LEDs and fluorescent lamps. A standard lightbulb converts only about 5% of the energy it receives into light, the other 95% being wasted as heat emitted to the environment.

References:
A. Burghart, B. Müller, W. Hanseder, 100 years of OSRAM – Light has a name, Munich, December 2006, available at: http://www.lamptech.co.uk/Documents/Companies/100%20Years%20of%20Osram.pdf (Accessed: 8.05.2021).
Lamp factories, “Lamptech” website, http://www.lamptech.co.uk/Factories.htm (Accessed: 8.05.2021).
Polska żarówka „OSRAM” S.A. (Warszawa/Pabianice), “Lighting.pl” website 1.07.2015, http://lighting.pl/Wydarzenia-branzowe/wydawnictwa-branzowe/Polska-Zarowka-OSRAM-S_A_-_Warszawa-_-Pabianice_(Accessed: 8.05.2021).

The Presto type Z radio receiver was manufactured by Towarzystwo Radiotechniczne Elektrit of Vilnius, which operated in 1925-1939, initially as a shop specialising in sales of imported radios and radio parts. Its profile was extended in 1927 by sales of radios of its own make. The company was established by Samuel and Hirsz Chwoles and Nachman Lewin. Due to the Jewish origin of the owners and of many members of the engineering staff (who were often discriminated against when applying for work in other factories, and employed in Elektrit for that very reason) on the wave of anti-Semitism that grew in Poland in the 1930s, the company’s products were often boycotted and considered “non-Christian”.
Presto is a seven-circuit radio receiver with four vacuum tubes. It has three wave bands: short, medium, and long. As the device has an untypical electrical system and is equipped with a small number of tubes, it is classified as a reflex system radio where one ABC1 tube serves a dual purpose; as a tube diode (rectifying tube detecting the signal) and as a triode (a signal amplifying tube). In this way, the radio signal received from the antenna is repeatedly processed in the radio’s system by the ABC1 tube, which replaces two other tubes. The radio is AC-powered (hence the letter “Z” in the type symbol). It has bandwidth adjustment, distance moderator, and tone adjustment.
The box of the Presto receiver has a horizontal layout. The chassis with electrical systems is enclosed in a wooden housing adorned with horizontal brass strips in the upper and lower part of the box, and on horizontal protruding strips of the fabric cover of the dynamic speaker (located on the left side of the front wall). On the right, in a square Bakelite frame, is a glass scale with the name of the company, the model, and the names of ranges and radio stations. Below it are two Bakelite knobs: a power and volume knob on the left, and a range and tuning switch on the right (long, medium, short wave and the gramophone function allowing the gramophone to be operated when connected). In the bottom part of the front housing there is a horizontal bar in the form of a semicircular, profiled plinth. At the back of the housing there is a masking wall, a power cord, connecting sockets for an external speaker, a gramophone, a ground wire, or an antenna.

Author: Filip Wróblewski

An electric projector is used for displaying slides on a projection screen. An image is put on a slide through which light passes, allowing projection of the image on a screen. The projector’s appearance harkens back to an early projection device called the laterna magica, where an image was projected from a hand-painted glass transparency. The earliest mention of projecting images using the laterna magica, and one of the first devices of this type was designed in 1645 by the German Jesuit Athanasius Kircher. In early projectors, the source of light was the flame of a candle or an oil or carbide lamp, which is why the device required a chimney to remove the combustion gases. Later designs were improved by adding a lens, the lamp flame was replaced by a light bulb, and glass transparencies – by photographic slides. The laterna magica was the predecessor of modern projectors such as the slide projector, episcope, epidiascope, as well as the photographic enlarger and film projector.
The Ornak portable projector was placed in a housing made of polished brass, which was a rarity. The manufacturer praised the design as not containing “any wooden parts or parts which can easily break or bend”. The device was designed to project images from slides on film. Thanks to the strong source of light passing through the lens in an elongated micro-projection attachment, it is possible to display images from a film roll divided into frames. The roll is mounted outside of the body on two rotary mandrels above and below the projection attachment. The Ornak projector was used in cultural and educational facilities, offices, and homes to display illustrated stories. The device was placed in a case that the buyer received for free with the purchase. The projector was sold in a complete set with a transformer, discharger, and micro-projection attachment. In 1935, the “Polacy Zagranicą” monthly magazine reported that the Ornak production facility had prepared an extensive catalogue of slides on a tape, illustrating subjects of knowledge about Poland, including geography, history, art, literature, military, aviation, industry and technology, religion, and stories and legends.

Authors: Piotr Turowski, Filip Wróblewski

The ZR-04 broadcasting system was manufactured in the 1980s by Zrzeszenie Przedsiębiorstw Przemysłu Elektronicznego Unitra. It was the final stage of communist Poland, which had an impact on the scale and methods of production of consumer goods. Society was becoming poorer, and the nation’s economy was struggling. Hence, for the electrical engineering industry, the period saw a major slowdown in comparison with the dynamic growth of the 1970s. The ZR-04 broadcasting centre is a material testament to such conditions. It is not an original device, designed from scratch, but a contraption put together from production overages. Several devices fulfilling complementary functions were enclosed in a single body – each manufactured by a different enterprise in the Unitra group. The ZR-04 broadcasting centre comprises: the MK 232P Automatic cassette recorder produced by Unitra Lubartów under licence from Grundig; the Safari 5 SMP 502 car radio produced by the Diora factory in Dzierżoniów; the G-902fs Emanuel gramophone from Fonica in Łódź; an Elektronika amplifier.
A broadcasting centre is the core of a wired public address system. It is the source station allowing creation, broadcasting, and application of programmes in the form of electrical signals sent via cables to receiving devices such as speakers. The device enables the management of a set of amplification devices embedded in the infrastructure of public utility buildings, such as schools, boarding houses, offices, railway stations, or facilities related to communal life – workplaces, prisons, or supermarkets. In this way, the broadcasting centre, using built in devices, as well as thanks to the ability to connect a microphone, allows transmission of diverse content using direct messages and musical recordings.
Devices of this kind first began to appear in the 1920s, when the first horn speakers and megaphones were developed and almost immediately found use in providing public announcements in public places, such as gathering areas or stadiums. As amplification devices were developed that could be used in cinemas, work progressed on systems for amplifying the electric signal, which allowed amplification of sound volume. At the same time, public announcement systems were introduced in schools in the United States, while in the Soviet Union they were used for propaganda purposes in factories, streets and collective farming establishments (Rus.: kolkhoz – which is why simple speakers with a volume knob were dubbed “kolchozniks”). In socialist countries such systems were widely used from the 1950s until the 1970s, when new means of communication began to take their place.

Author: Filip Wroblewski

The Atari 65XE computer of 1985 is one of nine 8-bit Atari microcomputer models manufactured in 1979-1987 as part of the XL and XE series.
Atari was established in 1972 and mostly produced electronic arcade game machines. In 1975 it began manufacturing home gaming consoles that connected to a TV set. One year later the company was acquired by Warner Inc., but the crash of the gaming market in 1983 weakened the company’s position. After a year, Atari was purchased by Jack Tramiel, who had left its competitor – the Commodore company – which he himself had founded. Atari’s expansion into Central and Eastern European markets was possible thanks to cooperation with local importers. Tramiel found a perfect business partner in Lucjan Daniel Wencel, owner of Logical Design Works (LDW), which operated in California, and its sister company – Karen, which was established with the Polish market in mind. This solution resulted in LDW becoming the sole distributor of Atari computers in Poland. The devices were sold in the Pewex chain of stores.
The Atari 65XE is a computer equipped with 64kB of RAM, 24kB of ROM memory, and a MOS 6502C CPU. It was manufactured in four versions, differing in the motherboard used. During The Winter Consumer Electronics Show in Las Vegas in 1985, Atari announced other models of this device apart from the 65XE: the 65XEM (XE Music Computer), a specialised music computer, and the portable 65XEP (XE Portable). On its launch, the 65XE was behind the far more modern 16-bit Atari ST series. It was equipped with the Atari Basic “C” interpreter, i.e., a program for parsing and execution of other programmes. It was the improved, debugged version of the Atari Basic “B” programming language. The Atari Basic dialect was developed in 1978 by Shepardson Microsystems, which used a pre-existing high-level programming language called BASIC (Beginner’s All-purpose Symbolic Instruction Code) developed in 1964 by John George Kemeny and Thomas Eugene Kurtz.
In the Atari 65XE, in line with the design standards of the 1980s, the main components are enclosed in a housing that also contains a four-row keyboard with a space bar in a separate line. To make the device work it was necessary to use the ports at the back to connect a monitor (or TV), a storage device (cassette tape recorder, a floppy disk drive, or a cartridge reader), and peripherals such as joysticks. The latter were based on the hand controller mechanism developed by Louis Blériot in 1909.

Author: Filip Wróblewski

The Koral OT 1722 television set, mass produced in 1963 by the Warszawskie Zakłady Telewizyjne, was a breakthrough design, which set the direction for further development of television sets in Poland. A prototype of the device was first presented at the Poznań International Fair in 1961.
The Koral television set was designed as a 19-valve, superheterodyne receiver with diversified methods of audio reception. It was designed to display black-and-white television and was equipped with circuits for 12 television channels in the OIRT (Organisation Internationale de Radiodiffusion et de Télévision) standard. It had autonomous contrast and brightness controls (reacting to the lighting in the room in which the receiver is located) and an automatic black control system.
A novelty in the design of the Koral TV set was the use of a 17-inch CRT with a large deflection angle (110°), as well as the use of printed circuits. This allowed vertical installation of the chassis, which can be tilted to give easy access to the inside of the receiver. The printed circuit board film was installed on one side of the chassis, and the electrical system components were installed on the other. Thanks to these modifications, the receiver had a compact, modern appearance. Its profile was flattened, which contributed to the design of a shallow housing. The top of the front frame was slightly bent into a characteristic “awning”, which was designed to shadow the screen. The front part of the fascia, made of painted aluminium, features tone adjustment buttons, a power switch, clarity adjustment (with the description “Film”), a channel switch and a tuning knob. The external appearance of the TV set was designed by Andrzej Latos – an artist employed at the Interiors Unit of the Industrial Design Institute. He was assisted in his design work by Olgierd Rutkowski and Stefan Solik.
Housings for the Koral television sets were supplied by Warszawska Fabryka Mebli, the CRT’s by Zakłady Usług Radiotechnicznych i Telewizyjnych, Łódź branch, and the speakers by Tonsil in Września. Thanks to the modern appearance and many technical amenities, the design of the Koral television set narrowed the gap between the quality of television sets manufactured in Poland and in Europe. Initially, the device was only sold for export.

Authors: Beata Krzaczyńska, Piotr Turowski

The item presented here is the Turkus television receiver. It is a mains-powered, twelve-channel superheterodyne with a black-and-white CRT and diversified audio reception methods. The design of the Turkus OT-1491 model was based on components used in the Belweder TV set, also designed by the Warszawskie Zakłady Telewizyjne (WZT). The housings of both models exhibit visual similarity, but the Turkus differs in not having a front flap for controls. Instead, the controls are placed at the front, underneath the device. Two knobs are placed on either side of the front wall – the power and volume knob, and the channel change and tuning control. The receiver design was prepared by the Studies and Designs Bureau of the WZT. Television receivers from the West were used as models in designing the receiver. The Turkus was manufactured in 1959-1960 by the Warszawskie Zakłady Telewizyjne, Poland’s largest enterprise producing TV sets. It is equipped with a colour filter, providing the impression of a colour image when placed in front of the screen. The illusion of watching colour television was only achieved for landscapes displayed on the screen, because the upper part of the filter was dominated by the blue colour imitating the sky, and the bottom part was intended to resemble grass. Between them, is an area of orange-like colour. The first colour television broadcast (from the session of the sixth Congress of the Polish Communist Party) was not made in Poland until December 6, 1971. Based on the electrical system of the Turkus, the WZT also produced the Jantar and Szmaragd television sets, which differed in the CRT used and the housing design.

Authors: Piotr Turowski, Filip Wróblewski

Throughout the 20th century, the incandescent lightbulb was the most widespread type of lighting, with a multitude of uses. It consisted of the following components: a base with contacts to the power source, a glass bulb, and a filament that emitted light as electricity flowed through it. It is impossible to name one single inventor of the lightbulb, as many researchers were independently researching the emission of light by a heated conductor connected to an electricity source. In 1854, the author of one of the most advanced designs that had the characteristics of today’s lightbulbs was Heinrich Goebel – an engineer and mechanic of German descent from New York. Over its long history, the lightbulb underwent many improvements. Before tungsten filaments became commonplace, lightbulbs were produced with filaments of osmium, tantalum, carbon fibre or bamboo. Experiments were even made with cotton fibres. Over time, tungsten was found to be the optimum material as it ensured good light efficiency and the high durability of the lightbulb. Initially there was a vacuum inside the bulbs, but experiments showed that the introduction of a chemically inert gas, e.g. argon, allows the life of the filament to be extended as it delays the process of evaporation during use.
This lightbulb was made in the Małopolska Fabryka Żarówek SA in Lviv, which had been operating from 1928 and was the successor of the Żareg lightbulb regeneration workshop. The plant produced Tantris lightbulbs of good quality. In 1931, it was bought by the lamp companies of the Phoebus cartel, and then liquidated in 1934.
Interesting fact: Before the incandescent lightbulb was developed there was another type of electric light source – the arc lamp – in which the light was emitted by an electric arc created between two electrodes separated by a small gap. Arc lamps were less efficient and had higher running costs than lightbulbs.

References:
Kalendarium historii polskiego przemysłu oświetleniowego, prepared by M. Kołakowski, “Lightning.pl” website 23.10.2008, http://lighting.pl/Wydarzenia-branzowe/wydawnictwa-branzowe/Kalendarium-historii-polskiego-przemyslu-oswietleniowego (Accessed: 8.05.2021).
W. Puciata, Żarówki, Warszawa 1937, document available at: https://polona.pl/item/zarowki,Njc4NjY4NTQ/2/#info:metadata (Accessed: 8.05.2021).
A. Burghart, B. Müller, W. Hanseder, 100 years of OSRAM – Light has a name, Munich, December 2006, available at: http://www.lamptech.co.uk/Documents/Companies/100%20Years%20of%20Osram.pdf (Accessed: 8.05.2021).

The theodolite is the basic measurement instrument used in land surveying and construction. It allows measuring distances between points in the field based on angles measured and trigonometric calculations performed. The main parts of a theodolite are the base plate (for mounting on a tripod), limbus (circle plate) and the alidade, i.e. the turning part, which includes the scope, among other parts. The presented repetitive (bi-axial) theodolite in the field in reference to geographic directions. The instrument was made in the Fabryka Instrumentów Geodezyjnych Gustawa Gerlacha in Warsaw in 1938 or a little earlier. The establishment operated from 1816 to the World War II, and it specialised in producing land surveying instruments such as the theodolites, levellers, rangefinders, steel squares, and topographic tables. The company also produced other, small accessories for land surveyors. Instruments from the G. Gerlach factory were considered to be on par in terms of quality with products of the most renowned German manufacturers, such as Zeiss. The company’s strong position was evidenced by international awards and the presence of its branch offices and sales outlets in several cities.
The presented unit was purchased by a Gdańsk land surveyor in G. Gerlach’s company sales outlet in Warsaw in 1938, and it was used in accordance with its purpose for more than a decade.

References:
M. Kluza, Polscy wytwórcy instrumentów naukowych w XIX wieku [w:] Polscy twórcy aparatury naukowej, red. A. Strzałkowski, Monografie series, vol. X, Kraków 2006, pp. 277–285.
G. Gerlach najstarsza polska wytwórnia sprzętu geodezyjnego, prepared by S. Walczak, exhibition catalogue of the Museum of Technology in Warsaw in accordance with the programme prepared by the Main Commission for Museums and Exhibitions of the Polish Surveyors’ Association, Warsaw, October 1973.