Colin Pykett Posted May 30, 2016 Share Posted May 30, 2016 A strange title? Yes, partly because I couldn't think of a better one. There is such a thing as the Aeolian harp which emits sound of its own accord when the wind caresses its strings. and it was a similar effect which my wife and I came across yesterday while out walking on the South Downs. We heard a distant, eerie yet compellingly beautiful sound as we approached a gate. It got progressively louder and it turned out to be generated by a gatepost made from a closed steel cylindrical pipe about four feet high and a few inches in diameter. It was pierced by three pairs of opposed holes at the top, middle and bottom which were presumably there to allow wires to pass through when performing its usual role as a fence post. As the wind speed increased the pitch of the note rose abruptly by a fifth, and it dropped when the wind died away. We heard it emitting three separate notes at different times, an interesting demonstration of mode-switching. The timbre was that of a rather loud stopped diapason. It was a fascinating example of organ pipe physics at work, and I intend to go there again to make some measurements of the pipe and also to record its sounds. It is also interesting that natural phenomena such as this (but generated by wood rather than steel tubes!) might have suggested simple wind instruments, and thus organ pipes, to our ancestors way back in pre-history. CEP Link to comment Share on other sites More sharing options...
David Drinkell Posted May 30, 2016 Share Posted May 30, 2016 By extension, anyone who has transported organ pipes on a roof rack will tell you that it is a good idea - to say the least - to arrange them so that the feet face backwards, so as to "avoid a symphony on the M4" as one person put it. Elsewhere, some pipes were being transported and met with an accident somewhere remote up in the hills. One got wedged by a gate-post and the place acquired a reputation for being haunted because of the unearthly sounds which could be heard when the wind blew. When thou from hence away art past Every night and all To whinny muir thou com'st at last And Christ receive thy soul. Lyke Wake Dirge (Poem of the Yorkshire Moors, as set by Benjamin Britten et al) Link to comment Share on other sites More sharing options...
Colin Pykett Posted May 30, 2016 Author Share Posted May 30, 2016 Loved the pun David (extension ... ) Maybe 'my' gatepost was actually the long-lost organ pipe you described? The gate in my message was only a few hundred yards away from a nice old church with a not quite-so-nice organ (a very early Allen digital with a couple of small speaker boxes wedged high up in the chancel roof). CEP Link to comment Share on other sites More sharing options...
John Robinson Posted May 30, 2016 Share Posted May 30, 2016 Along the lines of organ pipes and cars, I remember a previous car I owned had a sun roof which, when open and travelling at certain speeds, produced quite a powerful and deep pedal organ note inside the car. It was hard to specify a distinct pitch, but I swear it was within the 32' octave. How to produce a 32' pipe no longer than the interior of a small car! It brought to mind those 'cubes' I've read about. Link to comment Share on other sites More sharing options...
Colin Pykett Posted June 4, 2016 Author Share Posted June 4, 2016 Along the lines of organ pipes and cars, I remember a previous car I owned had a sun roof which, when open and travelling at certain speeds, produced quite a powerful and deep pedal organ note inside the car. It was hard to specify a distinct pitch, but I swear it was within the 32' octave. How to produce a 32' pipe no longer than the interior of a small car! It brought to mind those 'cubes' I've read about. Yes, I've experienced that with an open car window. The enclosed air in the car acts as a Helmholtz Resonator. Other examples are bass reflex (ported) loudspeaker cabinets, and the ocarina wind instrument. But car-sized organ pipes, while not being particularly long, would take up a lot of soundboard room! CEP Link to comment Share on other sites More sharing options...
John Robinson Posted June 4, 2016 Share Posted June 4, 2016 Yes, I've experienced that with an open car window. The enclosed air in the car acts as a Helmholtz Resonator. Other examples are bass reflex (ported) loudspeaker cabinets, and the ocarina wind instrument. But car-sized organ pipes, while not being particularly long, would take up a lot of soundboard room! CEP Ah, but where there are height limitations... ! Link to comment Share on other sites More sharing options...
David Drinkell Posted June 5, 2016 Share Posted June 5, 2016 Hmmm - Ouseley invented the Pyramidon, which seems to have been a similar sort of device. What should we call the examples above? Corollaphon? Toyotiana? Morgana? Link to comment Share on other sites More sharing options...
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