An interesting extract from a letter sent by 2^nd Lieut. Humphrey Arden (RGA) to his old school which was published in the school magazine.

Humphrey Arden attended the Dragon school, then   Radley and went on to Queens College Cambridge. He was about prepare for holy orders when war broke out. He was commissioned into the Royal Garrison Artillery in 1915. He died of wounds near Messines 6th June 1917 whilst serving with 156th Heavy Battery RGA. He is buried Bailleu Communal Cemetery Extension.

 CWGC Information: 2/Lt. Humphrey Warwick Arden      Dragon Portrait Gallery: 2nd Lt Humphrey Arden R.G.A.

2/Lt Arden obviously had a keen interest in Gunnery - So few think it worth while to understand guns, whereas really they are the most interesting things in the War.

2nd Lieutenant Arden outlines the lessons of Zone.

Source: The Skippers War 

“Those who are not gunners mostly have two delusions and if the same men rise to command without having learnt better, silly things will happen – but of that more presently.

A lesson that many Gunner has experienced over the subsequent years.

The two delusions are (i) that, when a gun is laid in such a way that the shell hits a particular spot, it will hit the same spot if it is laid in a similar way. With regards to the first, it is only necessary to remember that gunnery is a mechanical science and not a game of skill. Experts find out the laws of the science and the Royal Regiment follows the law. The personal element practically does not, or should not come into it.

With regard to (ii), it would take too long to explain the ‘error of the gun.’ But it is a fact that if a gun is laid in exactly the same way for a hundred rounds, the shells will cover an oblong some hundreds of yards long and several yards wide. This ‘zone’ varies according to the gun and the range – any gun being much more accurate for line than it is for range.

Royal Artillery Glossary of Terms and Abbreviations - Philip Jobson

Zone of the Gun - A series of shells from a gun firing at a given elevation will not fall in exactly the same spot but will be spread around the theoretical impact point....... It is impossible to guarantee to hit a precise spot and gunners need to be mindful of the zone of the gun when ranging onto a target.

2/Lt Arden outlines a situation where the gunners were mindful of the zone, however Those who are not gunners mostly have two delusions and if the same men rise to command without having learnt better

Take an example. 

Some months ago a cunning man thought unto himself a scheme. ‘We will bombard a piece of trench,’ said he, ‘and start at the outside ends together, gradually working in to the centre. The Boche will be forced to crowd in and finally will have to jump out of the trench and run for his life. Whereupon the Field and the Heavies (60 pdrs) shall slay him.’

Well, a Siege Battery was allotted some 200 rounds for the job and the trench selected was at right-angles to the line of fire, i.e the shells would have to drop at precisely the same range to a yard every time to hit the trench.

The Battery Commander calculated that 5 of the 200 might fall in the trench. That is to say. with the most perfect laying, ammunition and weather conditions, the gun itself could not put more than 2½ % of rounds in exactly the same spot at that range, and of course the ammunition, wind, temperature, barometer etc. never are perfect. So the Battery Commander did pretty well to get 3 of the 200 in the trench.

So if the desired effect requires 200 rounds on target. BC does well to get 3 in the trench, so taking account of zone, to get 200 in the trench , he would needed to have fired 13,333 rounds. As it was a Siege Battery it would be probably 4 guns, so 3,333 per gun. Imagine the logistical effort to achieve the effect !.

Taking zone into to account If this lot of shells were fired around 15 would roughly hit the same spot.

It looks like the Field and Heavies may have realised that this was not aplan that was going to be successful.....and put a brew on:

The Field and the Heavies waited in vain, or realising the fatuousness  of the whole proceedings, did not wait at all.

Rather than being asking for excuse for being didactic, it is a valuable lesson still for Gunners and Those who are not gunners and delusional. = ARTILLERY IS AN AREA WEAPON

You must excuse this didactic letter. So few think it worth while to understand guns, whereas really they are the most interesting things in the War.”