'Acoustic Shadow' in CW combat

[Josh The Lighthouse Guy]

A quick search reveals it to go basically unmentioned as happening during the Napoleonic Wars, which really should have showcased it occurring if it was as common a thing as the commonality of ACW claims would suggest

Not necessarily. Differences in weather/climate and battlefield topography between the two continents might make it less likely in Europe.

It's worth noting that most examples of the phenomenon were in 1862, a year of weather extremes. The two best known examples, Perryville and Iuka, occured only a few weeks apart in the western theater.

I agree some alledged instances of acoustic shadow are probably incorrect.

 

[Saphroneth]

Not necessarily. Differences in weather/climate and battlefield topography between the two continents might make it less likely in Europe.

I doubt the battlefield topography would have much influence, because the variety of battlefield topographies seen in Europe is extensive; ditto for the weather and climate.


The point about the weather extremes in 1862 is well made though. Actually, given that there's supposed to have been one at Seven Pines and there was a hell of a storm around then... perhaps it was just confusing the sound of cannon with the sound of distant thunder?

 

[Dead Parrott]

Think this phenomenon is real enough. Need to identify any episodes within battles where it was identified, then trace whether its occurrence affected command decisions and troop movements in a significant way.

A phenomenon can be both real and used as an excuse ( whether occurring in that instance or not).

The two are not mutually exclusive.

 

[Tom Elmore]

The Union Twelfth Corps approached Gettysburg on July 1, 1863, not knowing a major battle was in progress, which was cited as a reason for their slow response in moving up to render timely aid to the First and Eleventh Corps. I suppose a southerly wind, in addition to rolling hills, contributed to the sound masking. The humidity must also have been high. It was cited by more than one participant as I recall - perhaps a handful. I think, upon closer inspection, that shells were seen bursting in the air at a distance, but they could not be heard, so it was sight, not sound, that was the tipoff.

 

[Nathan Stuart]

Does Kenneth Noe's book about weather and climate in the war, The Howling Storm, address this issue?

Thanks. Have not read this title, but it sounds like an interesting and relevant work on the subject. Have read another work, 'Perryville', by Kenneth Noe and found it to be thorough and well-written.

 

[Nathan Stuart]

A phenomenon can be both real and used as an excuse ( whether occurring in that instance or not).

The two are not mutually exclusive.

Agree. Unfortunately, in many instances (during the period) it can be difficult to determine the truth of the matter.

 

[David Moore]

In the Battle of Iuka, acoustic shadowing prevented the coordination of Grant's planned envelopment of Price's Army of the West.

Troops did hear the sounds of battle from Rosecrans' side as this letter shows:

Action front," is the command, and we come round into position like the crack of a whip, the guns are unlimbered, and brought to bear on the road ahead and the limbers and caissons take position in the rear. Axes are brought into requisition, and every tree and limb that would impede the sighting of the pieces is leveled to the ground. The cannoniers take their posts and we wait. Old Gen. Ord rides by and looks with grim satisfaction at our bronze bulldogs. A half hour passes and no enemy, not even a shot in front. Presently an orderly dashes up, "Limber to the front," and we pass ahead followed by our Right Section which has come up. Another quarter mile, another hill, and again we take position. Here we stay untill [sic] evening, hearing brick cannonading to the right where Rosencrans is pushing them in. Is there nothing for us to do? Source: Civil War Letters: Thomas D. Christie, September 21, 1862 mnhs.gitlab.io ​

Are there any contemporary eyewitness accounts in which some one writes they didn't hear the sound of the battle at Iuka because of a wind inversion?

 

[James R.]

Not that I am aware of. My sources were the books "Battle Cry of Freedom" and "Vicksburg" by Donald L. Miller.

Troops did hear the sounds of battle from Rosecrans' side as this letter shows:

Action front," is the command, and we come round into position like the crack of a whip, the guns are unlimbered, and brought to bear on the road ahead and the limbers and caissons take position in the rear. Axes are brought into requisition, and every tree and limb that would impede the sighting of the pieces is leveled to the ground. The cannoniers take their posts and we wait. Old Gen. Ord rides by and looks with grim satisfaction at our bronze bulldogs. A half hour passes and no enemy, not even a shot in front. Presently an orderly dashes up, "Limber to the front," and we pass ahead followed by our Right Section which has come up. Another quarter mile, another hill, and again we take position. Here we stay untill [sic] evening, hearing brick cannonading to the right where Rosencrans is pushing them in. Is there nothing for us to do? Source: Civil War Letters: Thomas D. Christie, September 21, 1862 mnhs.gitlab.io

Are there any contemporary eyewitness accounts in which some one writes they didn't hear the sound of the battle at Iuka because of a wind inversion?

 

[Nathan Stuart]

Troops did hear the sounds of battle from Rosecrans' side as this letter shows:

Action front," is the command, and we come round into position like the crack of a whip, the guns are unlimbered, and brought to bear on the road ahead and the limbers and caissons take position in the rear. Axes are brought into requisition, and every tree and limb that would impede the sighting of the pieces is leveled to the ground. The cannoniers take their posts and we wait. Old Gen. Ord rides by and looks with grim satisfaction at our bronze bulldogs. A half hour passes and no enemy, not even a shot in front. Presently an orderly dashes up, "Limber to the front," and we pass ahead followed by our Right Section which has come up. Another quarter mile, another hill, and again we take position. Here we stay untill [sic] evening, hearing brick cannonading to the right where Rosencrans is pushing them in. Is there nothing for us to do? Source: Civil War Letters: Thomas D. Christie, September 21, 1862 mnhs.gitlab.io

Are there any contemporary eyewitness accounts in which some one writes they didn't hear the sound of the battle at Iuka because of a wind inversion?

Price attacked Rosecrans near Iuka (2 miles southwest), in the late afternoon on September 19 and the fighting continued into the night. Late that same day, Ord had been ordered by Grant, who was moving with Ord's headquarters, to deploy his divisions about 4 miles northwest of the battle, and was to await the sound of Rosecran's guns before advancing.

In his report, dated September 20, Ord merely wrote (without giving reasons), …"We are out of rations to-night. We didn't hear any sounds of the battle last p.m.."… ('OR': Series 1, Vol. XVII, Part 1, at page 70).

The following relevant extract from Sherman's own Memoirs appeared in the 'National Tribune' newspaper on October 22, 1896, at page 2:

…"Although Gen. Ord must have been within four or six miles of this battle, he did not hear a sound, and he or Gen. Grant did not know of it till advised the next morning by a courier who had made a wide circuit to reach them."…

In the same newspaper, dated September 29, 1898, Horace Greeley wrote below on the same subject at page 2:

…"not a shot had been fired from the direction where Ord's advance had been confidently expected – the excuse for this being that Ord had only expected to attack after hearing the sound of Rosecran's guns; and these a high wind from the northwest prevented his hearing at all….

…Ord…at 4 p.m., Sept. 19, …was directed to move his entire force – which had been swelled by the arrival of Ross's Division – to within four miles of Iuka, and there await the sound of Rosecran's guns.

Ross, in his advance, reported to him a dense smoke arising from the direction of Iuka, whence he inferred that Price was burning his stores and preparing to retreat. Next morning, hearing guns in his front, Ord moved rapidly into Iuka, but found no enemy there, Price having retreated….during the night"…

Could not find any personal accounts from members of any of Ord's units of whether or not a wind was present at the time.

From the piecemeal information above, it seems that Ord (nor Grant or any other commander in their contemporaneous reports read) did not, at least officially, mention the wind as a real reason for Ord (or Grant) not hearing the sounds of the battle. Wonder if the wind factor was concocted later on by reporters, like Greeley. Was there perhaps another reason why Ord (and maybe also Grant) didn't immediately respond to any sounds of combat heard during the evening of September 19?

 

[Nathan Stuart]

Given the frequent reference to 'acoustic shadow' noted in readings, am wondering whether it might be a blanket term conveniently applied to all instances where Civil War leaders were unexpectedly inactive with their commands in combat conditions. Other explanations for such failures to act by commanders could include negligence, plain disobedience, confusion, fatigue or temporary inability (say due to drunkenness). Need to firstly consider, then eliminate, each of these other factors that might have been present (if it's possible) for each situation examined.

Haven't seen an 'acoustic shadow' type reason mentioned in any Official Reports read. It seems to be an explanation label found mainly and commonly in modern secondary sources about the conflict.

 

[Reconstructed Rebel]

Haven't seen an 'acoustic shadow' type reason mentioned in any Official Reports read. It seems to be an explanation label found mainly and commonly in modern secondary sources about the conflict.

How well was this phenomenon understood in 1861? Had science documented its occurrence in non-war situations?

 

[Nathan Stuart]

How well was this phenomenon understood in 1861? Had science documented its occurrence in non-war situations?

Interesting questions.

Don't think the term was used at the time, judging by the the absence of references to it in the contemporary accounts and reports.

No doubting the existence of the phenomenon, by whatever description it's known, though. Believe the term is now firmly entrenched in the vocabulary of modern science.

My point is that it might be a widely bandied around term, perhaps applied haphazardly, by latter day military history writers, where some of the battle instances may not in fact be due to this phenomenon.

 

[David Moore]

Not that I am aware of. My sources were the books "Battle Cry of Freedom" and "Vicksburg" by Donald L. Miller.

Price attacked Rosecrans near Iuka (2 miles southwest), in the late afternoon on September 19 and the fighting continued into the night. Late that same day, Ord had been ordered by Grant, who was moving with Ord's headquarters, to deploy his divisions about 4 miles northwest of the battle, and was to await the sound of Rosecran's guns before advancing.

In his report, dated September 20, Ord merely wrote (without giving reasons), …"We are out of rations to-night. We didn't hear any sounds of the battle last p.m.."… ('OR': Series 1, Vol. XVII, Part 1, at page 70).

The following relevant extract from Sherman's own Memoirs appeared in the 'National Tribune' newspaper on October 22, 1896, at page 2:

…"Although Gen. Ord must have been within four or six miles of this battle, he did not hear a sound, and he or Gen. Grant did not know of it till advised the next morning by a courier who had made a wide circuit to reach them."…

In the same newspaper, dated September 29, 1898, Horace Greeley wrote below on the same subject at page 2:

…"not a shot had been fired from the direction where Ord's advance had been confidently expected – the excuse for this being that Ord had only expected to attack after hearing the sound of Rosecran's guns; and these a high wind from the northwest prevented his hearing at all….

…Ord…at 4 p.m., Sept. 19, …was directed to move his entire force – which had been swelled by the arrival of Ross's Division – to within four miles of Iuka, and there await the sound of Rosecran's guns.

Ross, in his advance, reported to him a dense smoke arising from the direction of Iuka, whence he inferred that Price was burning his stores and preparing to retreat. Next morning, hearing guns in his front, Ord moved rapidly into Iuka, but found no enemy there, Price having retreated….during the night"…

Could not find any personal accounts from members of any of Ord's units of whether or not a wind was present at the time.

From the piecemeal information above, it seems that Ord (nor Grant or any other commander in their contemporaneous reports read) did not, at least officially, mention the wind as a real reason for Ord (or Grant) not hearing the sounds of the battle. Wonder if the wind factor was concocted later on by reporters, like Greeley. Was there perhaps another reason why Ord (and maybe also Grant) didn't immediately respond to any sounds of combat heard during the evening of September 19?

Let me just say that after years of researching Iuka I haven't come upon evidence of anyone at the time mentioning an acoustical shadow. I've come upon edited accounts written after the battle. I've also come upon evidence that some of the principal participants did hear sounds of the battle. Hope to make this info public one day.

 

[ErnieMac]

An effect that seems to be the direct opposite of acoustic shadow occurred at Gettysburg. The cannonade that preceeded Pickett's Charge was reported heard at Baltimore and Pittsburgh. Pittsburgh is approximately 150 miles away as the crow flies.

 

[DanSBHawk]

From the piecemeal information above, it seems that Ord (nor Grant or any other commander in their contemporaneous reports read) did not, at least officially, mention the wind as a real reason for Ord (or Grant) not hearing the sounds of the battle. Wonder if the wind factor was concocted later on by reporters, like Greeley. Was there perhaps another reason why Ord (and maybe also Grant) didn't immediately respond to any sounds of combat heard during the evening of September 19?

There's no reason that Ord or Grant would not have attacked if they had known Rosecrans was fighting. Grant wanted to nail Price while he was separated from other confederate forces. But Rosecrans force was far behind schedule, and Ord simply did not hear the fighting once it started.

 

[David Moore]

Grant and Ord wouldn't have attacked if they weren't able to attack or delayed attacking. Grant was awaiting an answer from his suggestion to Price that Price surrender. He held back his attack until he received a response. The unsubstantiated acoustic shadow story would have been a convenient explanation for Grant's lack of action.

 

[Josh The Lighthouse Guy]

There's no reason that Ord or Grant would not have attacked if they had known Rosecrans was fighting.

Even if we play devil's advocate and suppose Grant and Ord wanted Rosecrans to lose, the timeline doesn't work. The Grant-Rosecrans falling out was the result of Iuka and the subsequent aftermath of Corinth. So there's not yet any motivation for a supposedly sinister Grant.

 

[Grant's Tomb]

'Acoustic shadow' = "I'm deaf with all this shooting!" That is why we wear ear defenders on range.

At the battle of Stone's River/Murfreesboro, the artillery was so thunderous that several men stopped fighting long enough to pick raw cotton from fields nearby and stuff it into their ears

 

[Reconstructed Rebel]

At the battle of Stone's River/Murfreesboro, the artillery was so thunderous that several men stopped fighting long enough to pick raw cotton from fields nearby and stuff it into their ears.

As an aside- I came across a comment in a memoir that after the war the most commonly cited disability for artillery men applying for a pension was deafness. Seems logical, although I've not seen statistics to back that up.

 

[Sheltowee]

As an aside- I came across a comment in a memoir that after the war the most commonly cited disability for artillery men applying for a pension was deafness. Seems logical, although I've not seen statistics to back that up.

Can't imagine anyone serving on an ironclad not being somewhat affected.