ECHOES FROM THE SKY
Echoes from the Sky by Richard N Scarth,
2nd Edition 1999, is an updated analysis of the development and use of
acoustic devices for the detection of aircraft from 1914 until 1940. This
very detailed volume starts with the development of sound ranging of German
artillery by officers of the Royal Horse Artillery at the start of the
Great War, led by a 1915 Nobel Physics Laurerate, Lt William Bragg. A
Lance Corporal of the Royal Engineers (TA) in his section, William Tucker,
later gazetted Major, helped solved one of the problems encountered by
inventing a low frequency microphone (Scarth 16). The very detailed index
does not include any listing of any Artillery corps, the whole story being
a Royal Engineers' show.
Tucker's life was later devoted to the development of the science of sound
location of aircraft and ships culminating in his appointment as Director
of Acoustical Research at the Air Defence Experimental Establishment from
which he retired in 1940. By this time Radio Direction Finding, RADAR,
had supplanted acoustical methods. Tucker is most closely associated with
sound mirrors in the south-east of England. No connection has been found
that associates him with the mirrors in the north-east including the one
at Kilnsea close to Spurn Head (Scarth Chapter 1 et seq, Flowers www).
Whilst Tucker was still on the Western Front, developments using concave
sound mirrors for the detection of aircraft had commenced on the Kent
coast under the guidance of Professor Thomas Mather FRS of the City and
Guilds (Engineering) College. A concave mirror was carved out of a chalk
face. Tests were carried out using an aircraft of the RFC in July 1915
but were inconclusive. Investigations were also underway at the RFC base
at Upavon in Wiltshire. (Scarth 24). Mather, in a report on a concrete
'reflector' of 16 feet diameter recommended:
The position chosen for a reflector should be the flat top of a low hill since such a position should be fairly free from local sounds. An absence of trees is also an advantage since the rustling of leaves interferes with the hearing. If mounted near the coast, say near cliffs, the reflector should be kept back say 200 to 300 yards (183 to 274m) from the edge of the cliff so as to eliminate the sound of the waves…. (Scarth 24).
At the time Professor Mather became involved, German airship attacks on England had created shock, horror and great public anger. Hull had been bombed with serious loss of life in June 1915. The location of the Kilnsea sound mirror on a low hill 350m from the beach meets Mather's recommendations. The unmistakeable topgraphy of Spurn Point and the Humber estuary made this location a favourite landfall for Zeppelin navigators.
Sound mirror at Abbot's Cliff, Kent (PBS)
Examination of the photograph above, enables the operation of the mirror to be deduced. On receipt of a 'Field-Marshal's Warning', from Horse Guards in London, of the approach of a Zeppelin picked up by tracking RDF and passed to the Admiralty's Room 40, a large stethoscope cone at one end of a dual-axis sighting tube was moved around the volume within the paraboloid until the focus of the concentrated sound was heard in the operator's stethoscope earpieces.[1] The azimuth and elevation of the sighting tube were then passed to a cooperating battery of searchlights and urgently notified to all other anti-aircraft units of the Humber Garrison and Horse Guards in London.
There is no doubt about the leading part the Royal Engineers played in the development of sound mirrors, a part that continued in the inter-war years. There is no evidence that the artillery units at Kilnsea provided the 'listeners' so it is necessary to visit searchlight operations there.
In acquisition of a target airship at night, searchlights played the primary part. This not only helped anti-aircraft artillery (AAA) but also guided fighter aircraft. Firstly, the sound mirror establised the line-of-sight to the target and enabled the searchlights to be directed on to it. Then the AAA, also provided with the target's coordinates, and watching the illumination of it by the searchlights, would be much more effective. "In 1915, the searchlight and anti-aircraft gun combination was what worried Zeppelin commanders" (Powis 15). This combination required close coordination. It is therefore reasonable to assume that the 'listener' was a member of the searchlight unit and was in touch with his comrades operating the searchlights positioned nearby.
On the Western Front it was the Royal Engineer Anti-aircraft Sections that operated searchlights. The members of these were electrical tradesmen, needed to service and operate the motor generator sets that provided energy to the carbon arc searchlights. Humber Garrison had the Electric Light Company (ELC) of the East Riding Volunteers, a Territorial Army Specialist Unit, under its command (Lock). They would man the searchlight battery next to the Kilnsea sound mirror. They would wear the RE's cap-badge. The 'listener' would be a member of the ELC, an RE (TA).
The AAA was manned by the East Riding Artillery Volunteers giving a cohesive response from TA units. This would be facilitated by a telegraph network run by the another TA unit, the East Riding Signals Company (TA) (Mitchinson 396). A Zeppelin commander, approaching the Humber estuary, would face a combination of units of the Territorial Army working together to bring about the destruction of his airship. "They included artillery, engineer and transport units as well as a telephone company in the East Riding formed to liaise with anti-aircraft defences" (Lock).
What part could J R R Tolkien played in this scenario? He had been seconded from the 3rd (Reserve) Battalion Lancashire Fusiliers to the 9th Battalion Royal Defence Corps. This was equivalent to a TA formation (Mitchinson 210). His medical category was not 100% after prolonged trench fever and he would be under the care of a Medical Officer at the nearby hospital (Flowers 142). He was a Signals Officer but exactly who his Signallers were is problematical. The Royal Defence Corps originally was formed of Protection Companies and Observation Companies. In July 1917 these were augmented by 18 'Battalions' (Mitchinson 333). An RDC Battalion could not be established with a Signals Section as they were raised ad hoc without the structure of a normal infantry battalion. It is probable that the East Riding Signals Company (TA) provided Signallers to this newly-formed unit, using equipment with which the battle-experienced Tolkien would be familiar.[2] Its telephone and telegraph network would connect the RDC Battalion HQ to each of the four companies and to the Humber Garrison HQ in Hull and to other nearby units. Tolkien would supervise an extensive signals network, maybe the principal reason Tolkien was seconded to the RDC. Tolkien would not be in command of the sound mirror operated by the Electric Light Company or any of its personnel but he would certainly be familiar with this great hunk of concrete listening out to sea.[3]
1. Stethoscope ear-pieces were designed to have a close
fit into the ear canal thus excluding any ambient sound. Headphones did
not have this ability.
2. The short-lived RDC Battalions were disbanded early in 1918 because
of shortage of officers and cost. They had recruited soldiers of between
41 and 60 with a low medical category, possibly because of wounds, and
who were not fit enough to serve overseas (Mitchinson 334).
3. Some Tolkienists suggest that Amon Llaw, the Hill of Listening, in
The Fellowship of the Ring, was created through a memory of J R
R of his time the vicinity of the Kilnsea sound mirror (Flowers www).
References
Flowers. M. Tolkien in East Yorkshire
in Something Has Gone Cracked pp.121-150. 2019. Zurich: Walking
Tree Publishers, Zurich.
Flowers. M. Web, In Tolkien's Genuine Footsteps: https://www.tolkiensociety.org/blog/2014/08/in-tolkiens-genuine-footsteps/
White W. L., Lock F. (Ed). Records of the East Yorkshire Volunteer
Force 1914-1919. 1920. Eastern Morning and Hull News. Hull (quoted
Mitchinson 230).
Mitchinson K. W. The Auxiliary Forces for the Land Defence of Great
Britain 1909 - 1919, 2002, PhD Thesis, University of Bedfordshire.
http://uobrep.openrepository.com/uobrep/handle/10547/622151
PBS Learning Media. Vidoe by Nova: Zeppelin Terror Atack. From
'Locating Zeppelins by Sound'. 2014. https://www.pbslearningmedia.org/resource/nvzt-sci-locatesound/locating-zeppelins-by-sound/#.XkVZ6iPgqUk
Powis M. Defeat of the Zeppelins. 2018. Pen & Sword Aviation
Ltd
Scarth R. N. Echoes from the Sky New Edition 1999 Revised and Expanded.
Independent Books, Bromley.
Acknowledgements
I am most grateful to Dr Nancy Bunting for her encouragement to dig more deeply, to Siân Mogridge, Archivist of the Royal Artillery Museum, for pointing me in the right direction and to Michael Flowers, noted Tolkienist, for his diligent search of the Records of the East Yorkshire Volunteer Force 1914-1919 held in the Hull History Centre. SH-K