Drop the Subject – (Part One)

We break out the wool tufts for a two-part story documenting the early days of streamlining. 

1936 Arrowhead. Bob Cunningham

In the 1930s they were widely publicised as the shape of automotive things to come, the so-called raindrop-shaped streamliners. That raindrops are tadpole-shaped is a common misconception however; falling raindrops are perfectly round. Ball bearing and lead-shot manufacturers exploit this phenomenon of falling liquids: molten lead is dropped from a great height into a cooling liquid with perfect spheres as a result.

Some raindrop cars made it to the actual volume production phase; early Tatras, the Fiat 600 Multipla and of course the SAAB 92-96 being amongst the best known examples, but most efforts would fail to find investors or public interest and remained one-offs or extremely limited production at best. Nevertheless some of the endeavours, initiated by people as diverse as a geneticist, a rocket scientist and a carrot juice maker are worthy and interesting enough to merit introduction on these pages.

1923 Persu. Georg Pahl

Persu: 1923

One of the earliest in the genre (although with its extremely long tail it can be argued to resemble the main body of a helicopter sans rotator blades as well) was devised by Romanian, Professor Aurel Persu (1890-1977), who studied engineering science in Berlin and graduated just before the outbreak of World War 1. Already during his studies the young Persu had received an award by the German Ministry of Education for his research into the behavioural features of spaceships and rockets in outer space; clearly here was an individual blessed with an unusually gifted and forward-thinking mind.

The Romanian prodigy continued living and working in Germany and was granted a patent in november 1922 for “An aerodynamically shaped automobile with all four wheels incorporated in the coachwork.” Count Ricotti’s Alfa Romeo and Rumpler’s Tropfenautos may have introduced the teardrop shape but their wheels were exposed; Persu’s was the first proposal for an aerodynamically correct automobile.

The inventor described his concept in his patent application as follows: “The coachwork shape resembles the upper half of a bird’s body (a pigeon for example), having a unified volume, of somewhat semi-circular cross-section with the base downward, higher and broader in front, about one third of the vehicle’s length whereupon the sections diminish gradually towards the rear. Given the shape of the coachwork, the chassis of such an aerodynamic automobile is implicit: the passenger seats will be placed in the more spacious front, the engine will be placed at the thinner rear, together with all organs of transmission and propulsion, which also allows for an equal distribution of the total weight on both ends of the car: all wheels must be within the outer—ranging surface of the coachwork free of over-structures, bulges, off-line headlights, steps or wings; the distance between the rear wheels will be therefore reduced according to the thinned out coachwork end, making it thus possible for the differential to be removed“.

Persu. Automobileromanesti.ro/ BMWblog.ro

In November of 1923 Persu started construction of his car. The body consisted of aluminium panels mounted onto a wooden frame. Powering the car was a 40 Hp watercooled four cylinder engine built by AGA Motorenwerke. 181 inches long and just 55 inches wide, the car had a wheelbase spanning 126 inches. Front and rear tracks differed substantially as dictated by the design concept: 48 inches up front and just 28 inches at the back.

Later tests have shown that Persu’s vehicle had a drag coefficient of just 0.20 which would still be very good today, although the highly unorthodox looks would most likely have presented an insurmountable hurdle in terms of commercial viability. With drive and fuel reservoir all mounted in the rear, question marks were raised about the road behaviour of such a vehicle; on the other hand Professor Persu used the car for many years as his daily transport and covered over 110,000 miles in it without incident.

The car’s presentation had not gone unnoticed and representatives from the American car industry (Ford and General Motors) expressed interest in Persu’s concept, but the Romanian declined to sell them the patent rights because no guarantees that his vehicle would actually be produced were provided.

Refusing to work for the Nazi war machine, Persu went into hiding in 1940 and returned to Romania after the war, planning to continue his science work there. Alas, the new communist regime did not trust him due to his past in Germany and made sure he was unable to find any position in the field he loved. Eventually, Persu found new meaning in his life at the Bucharest Symphony Orchestra; he had enjoyed playing the cello semi-professionally for decades and was considered good enough to be allowed to join the orchestra at sixty years of age. Persu was an orchestra member until 1969 when he retired at seventy-eight.

In that same year he retired his aerodynamic car as well and donated it to the Dimitrije Leonida Technical Museum in Bucharest where it is still on display, untouched and exactly as it was when Professor Persu handed over the vehicle. Having led a secluded life after his retirement from playing the cello, Persu passed away in 1977.

Worthpoint.com/ Autogallery .org.ru

Arrowhead: 1936

Wellington Everett Miller learned automotive design and drafting through a correspondence course and subsequently found employment with the renowned Murphy coachbuilding firm in Pasadena. Miller left Murphy in 1925, producing styling proposals on a freelance basis for GM and Packard, and in 1936 joined the Advanced Auto Body Company based in Los Angeles where he found fertile ground for his radically aerodynamic designs. That same year the Arrowhead Spring Drinking Water Company commissioned the AABC with the task of building an eye-catching and futuristic vehicle the company could use for promotional activities.

Miller did not disappoint and came up with a design for a radical streamliner; the name of the drinking water company displayed on a long vertical fin running along the centre of the roof. The major drive components, including the V8 engine were sourced from Ford but mounted in reverse; most parts of the chassis also being Ford items.

The three-wheeled Arrowhead was steered by its single rear wheel, mounted in a combination spring and shock absorber unit. As with Persu’s car the Arrowhead had aluminium bodywork on a wooden frame; forward vision was excellent via the one-piece curved windshield but not so good rearwards which was a common problem associated with this design concept.

Inside, the instrument panel, while again using standard Ford instruments and steering wheel was as radically different as the exterior of the Arrowhead but since the instruments were placed almost horizontally they were difficult to read for the centrally seated driver. Painted in fetching shade of light blue the Arrowhead was 204 inches long, 75 inches wide and 80 inches tall with a wheelbase of 125 inches.

Teleborsa.it/ Travelgumbo.com

The Arrowhead Spring Drinking Water Company was very pleased with the result and had their car, driven by a smartly uniformed chauffeur, appear at several celebrations, shows and events in the state of California. Much to their satisfaction the Arrowhead generated plenty of publicity in the written press as well as in newsreels shown in cinemas at the time.

After World War 2 intervened in the daily life of the USA the Arrowhead was retired and its fate is uncertain; in the 1980s an ex-employee of the company claimed having spotted the car on a transport truck near a garage but when he came back later to ask about it both truck and car had disappeared, never to be seen again.


Futurist illustrator Arthur Radebaugh had an illustration published as the cover of the November 1935 edition of the magazine Motor that showed a vehicle which resembled the Arrowhead in many aspects – so much so that some were of the opinion that Miller stole Radebaugh’s design. However, as teardrop-like vehicles abounded on countless magazine covers during this period it is more likely the resemblance was simply coincidental.

Part two continues shortly.

Author: brrrruno

Car brochure collector, Thai food lover, not a morning person before my first cup of coffee

11 thoughts on “Drop the Subject – (Part One)”

  1. Good morning, Bruno and thank you for yet another wonderful article. I never knew about Persu, such an interesting character and car. Same goes for the Arrowhead, I never heard of it and its creator before. It reminds me of Buckminster Fuller’s Dymaxion in overall layout, but the execution of the idea is different.

    Looking forward to part two.

  2. Rumpler Tropfenwagen (1921)

    Wind tunnel tests showed a cd of 0.28

    Alfa Romeo 40-60 HP Aerodinamica (1913)

  3. Good morning Bruno and thank you for bringing us an interesting history. I think Persu and Miller’s designs are particularly impressive because they were working without the benefit of wind tunnels and all the modern computer modelling and analysis that informs more recent designs.

    Your piece prompted me to find out when and where the first full-scale wind tunnel was built. It was apparently opened in 1931 at Langley Field near Hampton, Virginia. The tunnel was 60 feet wide and 30 feet high. It was used for aerodynamic testing on everything from World War II fighters and space capsules to submarines and modern jets. However, it wasn’t until the 1960’s that motor vehicles were routinely designed using wind tunnels.

    As a (trivial) aside, your mention of raindrops being perfectly spherical, and the promotional potential of the Arrowhead vehicle, reminded me of this:

    For those that do not recognise it, it a promotional vehicle built in 2005 for Birds Eye, a company that sells frozen foods. I saw it about ten years ago at the company’s offices in Lowestoft, Suffolk. It’s still there, as far as I am aware, but I doubt that it has ever been subjected to a wind tunnel to measure its drag coefficient!

    1. Hello Daniel,
      Thank you for the additional wind-tunnel info; that Bird’s Eye promotional vehicle is really cute and makes you want to take it home with you…. As far as its aerodynamics are concerned they should be pretty good as it is almost perfectly round. Practicality is of course another matter!

    2. Here’s the TV advertisement in which the ‘pea car’ featured:

    3. Great article brrruno! I’d be fairly confident that some suspiciously-low older cD figures can’t be accurately compared to modern ones, either because they were measured from models and scaled, limitations on equipment or other factors such as assumptions.

      Daniel, the “pea car” prompted me to think of a more famous orange Mini-based car that a quick search tells me was for Outspan oranges in the early ’70s. https://nostalgiacentral.com/pop-culture/fads/outspan-orange-mini/

  4. Good morning Bruno and thank you for another enlightening history story. I had not heard of either of the cars mentioned nor the Birds Eye one either. Really interesting stuff!

  5. Perhaps others share my minor fascination with the Arrowhead’s elegantly shaped headlamps…

    1. Hello Gooddog,
      I like them! And so did Chrysler, witness the retro-homage in the front end of the 1972 and 1973 Imperials:

    2. Indeed these are great – I knew them from the Cord L-29 and until now I thought they were exclusive to it:

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