THE SOUND OF THE GUNS.

Taihape Daily Times, 17 January 1918, Page 7

THE SOUND OF THE GUNS.

“DRUM-FIRE” ANALYSED

In no previous war have the reports from artillery followed each other so closely as to resemble the roll of a big drum. This phenomenon, first called “drum-fire” by the Germans, and now generally known by this name, is analysed by G. P. Sleggs in the London Times. Incidentally he shows that the sharp, distinct report necessary to yits (production is heard only in front of the gun, so that each side hears “drum-fire” only from the other’s artillery. The further one goes toward the roar of his own line, the more distinctly he hears the enemy’s fire and the louder it comes out above the muffled roar of his TTwn guns. Mr Sleggs vrites: “There is a fundamental and peculiar difference between the sound emitted by a gun and that of an exploding shell. When the gun is fired the sound-wave produced is of a totally different'nature from that produced by the burst of a shell. In the former case the impact of the gases leaving the. muzzle, as it were, ‘strikes’ the atmosphere in the direction in which the gun is pointed, but the burst from the shell causes a sound-wave of uniform intensity all around. Every soldier who has been to the front knows that if you stand in front of a field-gun or naval gun while firing even at a considerable distance —several hundred yards—the' crack is painfull} l ' intense to the ears, and may even cause injury, whereas it is possible to stand close behind the gun with comparative impunity. No such difference is observable with a shell.

THE ROLLING ORCHESTRA. “The wave of sound emitted by a gun is closely analagous to the wave of light emitted by a searchlight The intensity of the ray from a searchlight only diminishes gradually, and this analogy is borne out by the peculiar fact, familiar to those w'ho have been in the trenches, that the German machine-guns, or rifle-shots, always seem as loud wmether the width of ‘No Man’s Land’ is 70yds or 500yds. One of the most wonderful, and indeed majestic, of all sound phenomena in connection with artillery is the great Toll’ that follows* the discharge of a high-velocity gun. To hear this at its best, one must visrt a part of the front where the contour Is rugged, or where the landscape is well wooded, and where houses and other excrescences are abundant, as at 'Arras. The report of the cannon is followe at once and continuously by a majestic echoing roll that may be compared to a mixture of thunder and the music of a mighty bass orchestra. This rolling sound seems to travel forward as though it were following the flight of the shell, and is, indeed, mistaken by some for the actual sound of the shell.”

The real explanation, Mr Sleggs goes on to say, is that it is a series of echoes from the thousands of heterogeneous excresences in the surface of the landscape, combining to form a continuous trail of sound. The fact that this sound travels in the direction of the shell fits in with the search light analogy, as otherwise this chain of echoes would not appear to flow in any definite direction, and thus “one of the most grandiose aural phenomena that the ear can receive would not exist.

NIGHTLY DRUM TATTOO

The above considerations give rise to a remarkable" and surprising fact, which, indeed, arises in theory and is borne out in practice. This is, that at a certain distance and upward from the firing-line the sound of the German guns will be greater than the sound of our own, because we are in front of the German guns but behind the British, and although the latter

are nearer to us, yet the sound of the former wil appear louder and sharper because of the peculiar nature of the sound-wa\ e emitted fom the muzzle of a gun, the noise being nearly all concentrated in the direction of fire Thus, when approaching the firingline before an attack, the sound of the German guns often appears to preponderate over our own, giving one the apprehensive impression that the enem\ s artillery is in superior strength to our own, and it is only in coming into the artillery zon e that the British superiority is perceived.

“Another point illustrating this ’is the origin of the word ‘drum-fire.’ This term (Trommelfeur) was first used by the Germans to describe the. effect of our massed artillery on an unprecedented scale on the Somme. Now to the British,' who were. 0 f course, behind the direction in which their artillery was firing, this term ■would never have occurred,'Tor ’to be behind a British bombardment there is but little resemblance to a drummers tattoo, the whole sound being merged into a dull and heavy roar of guns; but to the German generals behind their lines every shot from the British, guns would stand out as a sharp, staccato note, the W’holo combining to give the impression of the rat-a-tattat of a mighty drum tattoo.