Cannons in the Canon 6: Overcharged

This is by far my favorite Neville cannon example. It's such an evocative metaphor and Neville calls on this metaphor in his deepest moment of despair.

As I have explained before, Henry Neville owned and operated an ironworks that produced cannons (ordnance) from the mid 1580s to the mid 1590s. This imagery, therefore, spans the entire Shakespeare canon. The timing matches with Neville's personal experience. A search on EEBO reveals this sense of "overcharge" (putting too much gunpowder in a a musket or cannon) to be quite unusual in printed English books at the time.

The fist example comes in Henry VI, Part II, 3.2; this sense could refer to a cannon or a musket of some kind:

QUEEN MARGARET. Enough, sweet Suffolk; thou torment'st thyself;
And these dread curses, like the sun 'gainst glass,
Or like an overcharged gun, recoil,
And turn the force of them upon thyself....

VAUX. To signify unto his majesty
That Cardinal Beaufort is at point of death;
For suddenly a grievous sickness took him,
That makes him gasp and stare and catch the air,
Blaspheming God and cursing men on earth.
Sometimes he talks as if Duke Humphrey's ghost
Were by his side; sometime he calls the king,
And whispers to his pillow, as to him,
The secrets of his overcharged soul;
And I am sent to tell his majesty
That even now he cries aloud for him.

Then we have Henry Neville writing to Robert Cecil from prison on 3 April 1602. I quote at length, spelling modernized. I urge you to read this very carefully and realize this was written approximately at the same time as Hamlet was written and/or revised. Note also that Cecil and Neville's wife Anne Killigrew were first cousins (their mothers were sisters). The use of "overcharged with grief" or "overcharged with sorrow" was relatively common at the time:

[I] beseech you to yield me your good favour in it as you have done in all the rest, that I may hope to have an end of my misery; which I do the rather and more instantly desire at this time in respect of my poor wife, whose state I do much fear, as being overcharged with grief & sorrow, besides my troubles, with the late loss of one of her children, and the likelihood to lose another: These afflictions coming one upon another I doubt will much endanger her weak body and mind, unless she may receive some comfort in some other kind: I beseech your Honour to take more compassion upon us.

And then we have Macbeth, 1.2 (this is considered another anachronistic use, just as iron ordnance in King John was anachronistic):

Yes;
As sparrows eagles, or the hare the lion.
If I say sooth, I must report they were
As cannons overcharged with double cracks, so they
Doubly redoubled strokes upon the foe:
Except they meant to bathe in reeking wounds,
Or memorise another Golgotha,
I cannot tell.
But I am faint, my gashes cry for help.

Here is an example from 1590 of the sense in which Shakespeare/Neville is using the word. Here is the wiki entry for "arquebus":

Certain discourses, vvritten by Sir Iohn Smythe, Knight: concerning the formes and effects of diuers sorts of weapons

whereas harquebuziers haue not onlie the same let, in case their peeces by ouercharging, or ouerheating, or crackes, or rifts, doo breake, but also if that through the negligence of the harquebuziers

And another example from 1594 by the same author:

[Certen] instruct[ions, obseruati]ons and orders militarie, requisit for all chieftaine

t in this case the mosquetiers must take great heed, that they do not ouercharge their peeces with powder, nor with aboue the nomber of:5: or:6: haileshott of warre at the most, as aforesaid; least that their peeces should break or recoile, and so ouerthrow them to the trouble of the piquers, from vnder whose piques they are to discharge their peeces: and this manner of discharging of haileshot of warre by mosquetiers is for diuers times and places of seruice, of great effect, so as they giue no volee at the enemie aboue:20: paces at the furthest