Marconi's Attic Laboratory

Marconi's Laboratory (1)

A re-construction of Marconi's laboratory as it would have been in the Spring of 1895 when he sent his first Wireless signal. A working Spark Transmitter is on the table to the right of the window and this is demonstrated during the tour by the Museum Guide.

 

Marconi's Laboratory (2)

Again set up as it would have probably been in the Spring of 1895. The work being undertaken (difficult to see in the photo) is the construction of a coherer - the vacuum pump (partially filled with mercury) is on the front right edge of the work bench.

 

Marconi's Laboratory (3)

A view of the left hand part of the laboratory showing Marconi's desk (foreground) and another workbench by the wall. Centre left is a double barrelled shotgun. Marconi's brother, who assisted Marconi with much of his early work at Villa Griffone, used a shotgun to signal to Marconi reception of the transmitted signals at Celestini Hill - approximately 1 mile away.

 

Marconi's Laboratory (4)

Most of the Attic Laboratory now houses a mixture of static and interactive displays and exhibits which visitors may freely use, together with other educational materials and displays.

One of these interactive displays includes a working spark transmitter (and yes - you can send CQ on it!) and a reconstruction of a early coherer based receiver. The spark transmitter is on the far yellow table - the orange cylinder is the spark coil, and the receiver is on the yellow table in the foreground. The transmitter and receiver are enclosed in perspex covers for safety. In particular it is very interesting to see the operation of the coherer receiver which needs to be mechanically vibrated to "de-coherer" the Nickel filings contained within the coherer element.

The invention of Wireless was in fact the culmination of a series of discoveries and inventions by a number of different individuals, and certainly there were others also experimenting with apparatus that could have ultimately led to the discovery of Wireless. By visiting the laboratory you get a very good impression of the hurdles Marconi needed to overcome before he could send - and more importantly receive his first wireless transmission.

Although the young Marconi was familiar with the discoveries of Heinrich Hertz in 1888, much of Marconi's work involved the detection of Thunderstorms - and this work brought about two important stepping stones in the story of the development of Wireless.

The first was the development of the Coherer detector - an evacuated tube with metal (Nickel) filings which exhibited detection properties in the presence of high frequency signals as generated by Lightning. Marconi did not invent the coherer - the effect that a tube of iron filings becomes conductive by action at distance by electrical sparks was first discovered in 1879, and it was Oliver Joseph Lodge who coined the term "coherer" in 1894. Although Marconi was no doubt aware of these papers, he nevertheless had to construct and refine these concepts into a usable device, no mean feat given the technology available at the time. Although very crude by todays standards, the Nickel filings Coherer is sensitive to signals at sub-microwatt levels.

Next followed what is really a logical progression and could be considered as the young Marconi's most important single action. This he described when he received the Nobel Prize in 1909 :

"In August 1895 I hit upon a new arrangement which not only greatly increased the distance over which I could communicate but also seemed to make the transmission independent from the effects of intervening obstacles.

This arrangement consisted in connecting one terminal of the Hertzian oscillator, or spark producer to earth and the other terminal to a wire or capacity area placed at a height above the ground and in also connecting at the receiving end one terminal of the coherer to earth and the other to an elevated conductor."

The Antenna had been invented and Wireless was born.

 

 

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Last update 6 Oct 2003