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The Sound Man - George Constantinesco and Sonic Power Transmission

Barrie Blake-Coleman

Had you been around in 1926 and had at hand a copy of the popular magazine 'Graphic' you would have come across  a  page featuring a montage of 17 faces headed by the title '1900-1925: Leaders In The March Of Progress'...

Many readers of the 'Graphic' at that time would have had no trouble in recognising the faces of the scientists and engineers portrayed in the 'March Of Progress'.  Einstein, Edison, Bell, Kelvin, Marconi, Dewar, Orville Wright and several other worthies were featured. Surprisingly, absent was the face of Nikola Tesla, famous for his many ubiquitous inventions in electricity and general engineering -  a very curious omission. And yet, in his place and even more mystifying, was a face we, nor many at the time, would recognise at all, that of George (or Gogu) Constantinesco.


So how was it that an émigré to England, from a then impoverished and economically backward Eastern European state like Romania, came to occupy the same status in a galaxy of so many other eminent and distinguished scientists, engineers and inventors? 


For one thing, he amassed some 134 granted British patents with possibly another 150 inventions never filed for a patent. Over his life he was responsible for a total of 319 patents filed in France, Germany and the UK, mostly dealing with the control or transmission of motive forces through  liquids and solids. For another, he held the gratitude of every British fighter pilot of the

first world war as the inventor of the hydraulic interrupter gear that made it possible for allied aircraft to fire their machine guns through rotating propellers. Better, it was said, than the Fokker designed (and somewhat less reliable) interrupter used on German machines.


Moreover, the ever burgeoning automobile market was to give thanks to his sonic oil drilling technique, making it possible to drill deep wells in half the time usually experienced.  Indeed, his interest in acoustics and sound, and its application to engineering, made him virtually unique in his inventions and various engineering applications. Unlike many inventors then, it was 'sonics', the application of vibratory or sound transmission to convey energy and power, that was Constantinesco's forte, and accounted for the greater part of his inventive output throughout his life.   


Constantinesco was born in 1881, the son of P.G. Constantinesco,  a teacher of mathematics and engineering at the Nikolai Balcesca Institute in Craiova, Romania. He was well tutored by his father, not only becoming an expert mathematician but a more than competent pianist. His interest in sound and acoustics began with his music, and the designing of a hearing trumpet to mitigate his mothers oncoming deafness. The episode involved him attempting to model the complex harmonic interaction between the eardrum and the horn's acoustic characteristics. 


On leaving school he entered the L'Ecole National des Ponts et Chausees, the elite French civil engineering school in Paris. Here, he spent the years 1898 to 1904 studying, subsequently passing out at as the top student of his year. Almost immediately, he took up a senior post in the Romanian Ministry of Public Works.



As a civil engineer, he was tasked with designing and building major state funded civil construction projects. He was well ahead in the theory of utilising reinforced concrete,   a material still at this time treated with deep suspicion because of its unpredictable behaviour and the number of disasters occurring from its use. He had already crossed swords with his department professor Saligny regarding this -  being repeatedly told 'not to build bridges out of reinforced concrete'.  "You told me that before", he had replied, "But that doesn't mean I won't build them!" and build them he did, some of which are standing today.


On one occasion in1906, faced with the imminent collapse of the new Romanian Chamber of Deputies (incompetently constructed under the control of architect Samarendescu), Constantinesco threw up a reinforced girdle of concrete and proceeded to underpin the rest of the building with reinforced concrete floors and columns. However, the Deputies refused to enter the finished building for fear it would disintegrate around them. The Minister of Finance complained bitterly that Constantinesco had been 'irresponsible' and demanded an inquiry. Before the presiding expert, a Professor Ionesco, could begin a formal investigation,  Constantinesco brought in hundreds of sand filled sacks and loaded every horizontal surface of the building until he had exceeded the practical loading by 50%. Ultimately satisfied, and now with Constantinesco well vindicated,  the Deputies eventually moved in. But, Constantinesco deliberately left them to organise the removal of the remaining overspills of sand!

At 26, Constantinesco took out his first British patent on elevated monorail construction, then a new transport technology. At this time he was still in Bucharest and a government employee, but already beginning to resent the operational constraints imposed on him by his work. In 1908 he left his employers and set up as an independent consultant with a colleague Tiberius Eremia. He was commissioned to build several bridges and was said to have laid the earliest examples of tarred roads in Europe. It was as he supervised construction through the Carpathian mountains that he was to have his genesis into mechanical engineering.


He recounted that it was at this time he saw his first motor car - in this respect a car driven by an American, one Charles F. Kettering. Kettering was an experimental engineer, about to resign from National Cash Register and start his own development of automobile technology. Already highly inventive, Kettering was to make profound contributions to automobile engineering and on meeting Constantinesco found a kindred spirit.

Kettering told Constantinesco about how in the U.S and Britain science and technology was fostered by a long record of success, and if he wanted to pursue invention he needed the right environment.


George Constantinesco arrived in London in the autumn of 1910 with the option of visiting Kettering in the US. He had already filed a second British patent for a vehicle air carburettor and it was clear that he was determined to move into automobile and mechanical engineering - he was no longer a civil engineer.


Constantinesco had arrived in England (apparently well financed from his Romanian consulting businesses) and between 1911 and 1912 had filed eleven more patents all related to the internal combustion engine. Later between 1912 and 1913 he was experimenting with sonic transmission, particularly as applied to a sonic rock drill. At the same time he took up Keterring's invitation to visit the US and while there he spent a short period at Menlo Park with Thomas Edison. Though almost diametrically apart in their respective interests, for Constantinesco it was a stimulating engagement.


At this time most of Constantinesco's work in England was carried out in a laboratory located on an island in the Thames near Twickenham; initially trying to perfect a marine power transmission system based on hydro-sonic principles. This depended on the propagation of compression waves through a media.

Here appeared the beginnings of his quest for motionless power transmission - by utilising a train of rapid pulses in both liquids and solids. There was no true displacement of the media - a liquid did not flow, nor a solid metal turn or bend, it depended on the waves of compression and relaxation which propagated away from a vibratory source and moved through the medium as a sound wave would.


His attention to his experimental work was disrupted in the winter of 1913 when heavy storms threatened to cause his island sanctuary to be flooded and he only just escaped before the bridge linking the island to the mainland was swept away. Luckily, he had formed a friendship with Walter Haddon (1864 - 1938), who had trained as a printer and owned the print and type founders Haddon and Co. Haddon had an inventors inclination, having already developed improved printing and type casting methods. He was good at business and was very inclined towards the potential of Constantinesco's work. Wanting matters to progress, he provided a new laboratory for Constantinesco in central London at Alperton (Brent) situated near the Regent's (Grand Union) Canal.  Here, Constantinesco began to determine a complete theoretical approach to his 'sonics', based essentially on electrical theory.


In 1914 he married a long time sweetheart Alexandra (Sandra) Cocorescu and moved to Weybridge after the birth of their son.

As the first world war began in 1914 the development of aerial combat saw rapid advances in both aircraft, air weaponry and tactics. Fighter to fighter combat saw allied aircraft outclassed as German machines began to employ twin machine guns firing directly through the airscrew. Attempts to do the same with allied aircraft were initially disastrous. Some tried using metal deflectors fixed on the wooden propeller blades so that bullets, failing to find a free path between the blades, would not destroy them as they struck. The Vickers company tried, as too others (Scarff - Dibowski, Sopwith -Kauper) but every mechanical system, using cams and push rods, failed to guarantee the synchronisation between the flight of the bullet and the momentary free space between each revolving propeller blade. The problem was that the airframe invariably flexed in flight (especially in combat) thereby changing the dimensions of the rod linkage displacement triggering the guns. Since timing-tolerances needed to be kept to milliseconds, this could mean a severe loss of synchronisation as the guns fired and, thereafter, the total destruction of the airscrew. 


Constantinesco's C.C. Interrupter Gear as he called it was demonstrated in May of 1916 and because it was a sonic hydraulic system it completely eliminated the airframe flexing problem.

However, to hide the still esoteric principle of sonic propagation, he insisted it was based on liquid compressibility (rather than a 'sonic' wave train propagated through the liquid  - which it was). At once, his device was ridiculed as scientifically impossible. He was derided as a 'mad Romanian' and at first it seemed that his 'Interrupter' was to go the way of other hopeful, but impracticable, solutions.  However, a member of the Department of Military Aeronautics, one Major Hopkinson, on his own authority gave Constantinesco an order for twelve sets of his Interrupter at £50.00 per set. On fitting the sets they were found to be utterly effective and over the war years he was to manufacture and supply through sub-contractors some 55,000 units. Constantinesco never organised personal manufacturing facilities for his technologies but by sub-contracting out nation-wide to various companies (under his own demanding quality control agreements) he met all the orders given to him.


Improvements came about as certain operational problems were discovered. Sir Hiram Maxim visited Constantinesco in his laboratory and was sceptical that the Interrupter could ever work. His experience with the Maxim machine gun had taught him that 'the velocity of individual bullets varied as they were fired because the percussion could be delayed and the level of cordite in the cartridge and weight of the bullet could vary!'

There had been reports of the occasional round taking off a sliver of wood on a propeller and since no fault could be found in the Interrupter it resulted in even better quality control of cartridge production;  including the percussion cap, cordite load and bullet weight. Indeed, the Interrupter was widely used as a method of determining quality control of small arms munitions.


Though he had disguised the principle of operation of the Interrupter, he was determined to prove his theory that liquids were significantly compressible and that it was perfectly possible to demonstrate and utilise the phenomenon. We now know that followers of Constantinesco, like Dowty, Amagot, Taylor and Bridgeman, all made significant applications in liquid compressibility (Dowty et al used it for liquid springs used in aircraft landing gear) but Constantinesco was the first to irrefutably prove that it was realisable and useful. In 1915 he disproved the fallacy of liquid compressibility by demonstrating a silent mortar that was capable of launching a 90 Kg projectile well over 1400 metres. It employed super compressed oil at 25,000 psi. Another example compressed a volume of water at 30,000 psi (some 2,000 atmospheres) reducing its original volume by 30%.

By early 1918 Constantinesco had built a reputation as a major contributor to the war effort. No longer the object of sneers and denigration the Admiralty wanted more from him and financed the erection of a sonic's laboratory at West Drayton west of central London. Here he pursued a broad range of experimental approaches, the most noteworthy being a high frequency (12 Khz) pulsed diesel pump injector for submarines which, because it was effectively silent, removed the submarines main sound signature while underwater. At this time also Constantinesco had completed his monograph 'Theory of Sonics' and, always obliging, the Admiralty agreed to publish it as a limited edition. However, though his patent on the diesel injector remained secret until hostilities had ceased, the Germans renewed the war when the Bosch company infringed the patent thereby leading to long and bitter litigation in the courts. So protracted was the whole process that Constantinesco never benefited from his invention.


Almost as the armistice was announced, the Admiralty closed down Constantinesco's West Drayton Laboratory and he found himself stranded with no base to return to. Rather disillusioned and disappointed, he returned briefly to Romania where given the freedom from wartime exigencies his fertile mind generated more ideas and he quickly returned to England. He had however benefited from the British governments 'Awards to Inventors' scheme for wartime contributions (£10,000) and his 'Interrupter' and other inventions had also brought in a substantial income. As such, Constantinesco was able to fund further developments.


However, by the early 1920's his marriage to his wife Sandra had by this time started to fail, and the turmoil of the break up impeded the impetus of his new inventive developments. He then remarried, this time to Eva Litton who brought with her a ready-made family, having two children from a previous marriage. They moved to Lake Coniston in Cumbria and set up home. Because of all this, it took a few years for him to arrange the facilities he wanted for his new projects.


In 1923 Constantinesco was ready to demonstrate a completely unique way of driving the wheels of a motor car. His approach was mechano - sonic rather than hydro-sonic method. A 500cc motor transmitted pulses through a fixed non- rotating drive shaft which then converted the vibrational energy into rotary motion through an ingenious torque converter. There was no need for a gearbox or clutch, the engine speed determined the velocity of forward motion and as demonstrated in public, his car could reach 48 km.p.h with a fuel efficiency of some 35 Km per litre. The central design feature, the torque converter, depended on the incoming vibrational train oscillating a pivoted mass which in turn moved oscillating links and levers. A principle that was so esoteric and difficult to analyse that even Constantinesco was at a loss to fully clarify it (see Diagram).


It took Constantinesco a series of five articles in the auto magazine of the time, Automobile Engineer, to justify and champion his invention, all of which ran to nearly 30,000 words. The result was a heated and rancorous debate with several other well known authorities in the field, none of whom accepted his challenge of a £100 prize if they could  disprove his mathematics or reasoning. And yet, his car never became a production reality nor was the principle taken up by others, though in a period where fuel was cheap and production costs tied to established engineering, there was little incentive. Moreover, the weak aspect of Constantinesco's technology was the torque converter, which had limited durability.

However, he was determined to prove a point and at the Wembley Exhibition of 1924 he demonstrated a railway locomotive driven by his mechano-sonic system. Though he had no success in attracting it's introduction into the British railway system  it was adopted by his home state and railcars driven by two diesel engines ran on Romanian rural lines for some time.


It was to be Constantinesco's 1918 book, 'Theory of Sonics' that led to his next major success. A Dr. I. Basgen had observed that sonic vibrations, imposed on rotary rock drills used in oil prospecting, encouraged the return of circulating mud which carried rock particles back to the surface. Constantinesco had experimented in a similar way as far back as 1912 and his principles of sonics had also shown that hitherto noisy industrial methods, such as hammer drills, road surface fragmenters and the like could all be improved to virtual silence by incorporating sonic principles. Likewise, he showed that a three phase sonic generator could also transmit heat to considerable distances. This thermo-sonic method was used to disrupt the formation of paraffin waxes in oil field boreholes.


Constantinesco continued invention in his workshop on the shores of Lake Coniston until his death in December 1965.


If anything, Constantinesco was only grudgingly acknowledged as an innovator by his peers, even though the great and the good (Raleigh, J.J Thomson, Charles Parsons etc) are all known to have visited his laboratory. His appearance in the 'Graphic's  March Of Progress may well have been as the result of influence from one of these men rather than a popular appreciation.  It was perhaps the highly unconventional physical principles in which he worked that created the scepticism with which his inventions were received. Furthermore, he failed to create a viable industrial reputation, receiving very little in industrial support, making available very little that industry could easily capitalise on. He struggled in a time where the materials available to him were less than ideal for meeting the physical principles in which he worked. 


Though he was prolific in invention, only a few of his inventions were outstanding (though, in truth, the same could be said of many others).  And yet, it may well be that in the future 'Sonics' will become a central principle of civilisation's power and heat transmission methods - it only requires another Constantinesco to make it possible.




The author particularly thanks, among others,

The British Library

The Bodleian Library Oxford

George Constantinesco sometime in 1935.

Constantinesco Concrete bridge in Carol Park, Bucharest, dedicated in 1906.

WWI Dogfight

Sopwith Interrupter

CC Patent 1918

Charles F. Kettering


Menlo Park

The Sonic Laboratory at West Drayton in 1918.

Trench mortar based on compressed liquid. It could silently send a 90kg explosive projectile 1400 metres.

The famous 'Interrupter' Gear. Sonic generator and trigger mechanism.

Automatic 500cc converter engine. The inertial elements are at the top right.     

Paris motorshow 1926. Two torque converter cars.

George Constantinesco in his workshop using a variable speed sonic lathe about 1923.

250 HP Locomotive driven by a sonic converter at  the Wembley Exhibition of 1924.

Diagram showing the principle behind the torque converter. Changing the displacement frequency  changes the power output.

First car using a sonic torque converter driven by a 10HP motor.

George Constantinesco/

Gogu Constantinescu

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