What did Tennyson intend to say, by 'fierce light that beats upon a throne and blackens every blot'?

Question

Source: Rebecca Gowers. Plain Words (2014 ed). p. 270 Top.

  The fact is not that officials do uniquely badly but that they are uniquely vulnerable. Making fun of them has always been one of the diversions of the British public. The fun sometimes has a touch of malice in it, but the habit springs from qualities in the British character that no one would like to see atrophied. The field for its exercise and the temptation to indulge in it are constantly growing. De facto executive power, which during the seventeenth and eighteenth centuries moved from the King to Ministers, is being diffused lower still by the growth of social legislation. The theory that every act of every official is the act of his Minister is wearing thin. [The preceding sentence isn't in the 2014 edn, but was in this online edition that Google yielded.] Tennyson's “fierce light that beats upon a throne and blackens every blot” is no longer focused on the apex; it shines on the whole pyramid. So many people have to read so many official instructions. These offer a bigger target for possible criticism than any other class of writing except journalism, and they are more likely to get it than any other class, because a reader’s critical faculty is sharpened by being told — as we all so often have to be nowadays — that he cannot do something he wants to, or must do something he does not want to, or that he can only do something he wants to by going through a lot of tiresome formalities.

I learned from Google that the emboldened quote is from Idylls of the King. But what exactly did Tennyson intend by:

1. 'beat upon'?

2. 'blackens every blot'?

If a light is shining on a throne, then wouldn't it brighten, and not blacken, the blots on the throne?

Answer 1

As to 1, the sun "beating" is a common way of saying the sun was shining very brightly, oppressively brightly. One of the senses of "to beat" in the OED is "transf. Of water, waves, wind, weather, the sun's rays, and other physical agents: To dash against, impinge on, strike, violently assail"; one of the citations is to Spenser: "The Sunnebeame so sore doth vs beate." (1579). (The 1962 movie Lawrence of Arabia had a scene where the protagonists had to cross the "Devil's Anvil", an especially hot bit of desert; here the figure is that just as a blacksmith's hammer beats the anvil, so the Devil beats the anvil (the Nefud Desert) with his hammer (the bright sunlight). The Devil, of course, is associated with heat and fire. The 1967 rock band, the Devil's Anvil, borrows this kenning, both in its name and its album art.)

As for 2, dirt is more visible in bright light than in dim.

Tennyson means something like "intense scrutiny is focused on the monarch, and flaws become visible." Gowers means something like "and on all the rest of the government, too."

Answer 2

The context of the Tennyson quote is a eulogy to Prince Albert, in the Dedication of Idylls of the King (and therefore the implied context of a connection to King Arthur?)

Not swaying to this faction or to that;
Not making his high place the lawless perch
Of winged ambitions, nor a vantage-ground
For pleasure; but through all this tract of years
Wearing the white flower of a blameless life,
Before a thousand peering littlenesses,
In that fierce light which beats upon a throne,
And blackens every blot: for where is he,
Who dares foreshadow for an only son
A lovelier life, a more unstained, than his?
Or how should England dreaming of his sons
Hope more for these than some inheritance
Of such a life, a heart, a mind as thine

The first and last parts of this excerpt are clearer than the middle part, at least to me. Tennyson is talking about an exemplary royal who never acted poorly or misused his position, and saying that a life such as his is the best anyone could ever hope for their sons. That leaves the few lines that Gowers quoted and that you're asking about:

Before a thousand peering littlenesses,
In that fierce light which beats upon a throne,
And blackens every blot

I believe this refers to those who might criticise Albert: the "peering littlenesses" being something akin to busybodies, "little" people who "peer" at his life in an attempt to find fault.

With power comes responsibility, and with fame comes visibility: a royal figure will naturally face more scrutiny than someone in a lesser position. Tennyson refers to this fact by a colourful metaphor: the scrutiny to which royals are subjected corresponds to "fierce light" shining upon the "throne" which metonymises the monarchy, and any misdemeanour of theirs which comes to light under such scrutiny corresponds to a "blot" revealed by that fierce light.

For a more modern example, consider Donald Trump. His utterances on Twitter nowadays make international headline news, in a way which they never did before he became president of the USA. His position of power exposes him to more scrutiny - and more criticism - than he would have had otherwise. The "fierce light" of the media shines upon everything he says, and each time he misspeaks it's like a "blot" on his presidential record, made blacker and more visible by the attention accorded to his position.

1. For the sun to "beat upon" a surface is a common phrase: see, for example, the derived adjective sunbeat. It is perhaps most often heard in the phrase "beat down":

   If the sun beats down, it shines very strongly and makes the air very hot

2. No: a bright light makes dark blots seem darker, not brighter. In the shade, darker and less dark patches are more similar, and the blackest parts don't stand out so much. In bright sunshine, the blackest blots remain black while the rest is lit up, and stand out more by their contrast.

Going back to the Gowers text which refers to the Tennyson quote:

The theory that every act of every official is the act of his Minister is wearing thin. [...] So many people have to read so many official instructions. These offer a bigger target for possible criticism than any other class of writing except journalism, and they are more likely to get it than any other class

What the writer is saying here is that government officials, not just the ministers who lead the government, are liable to receive fierce criticism from the public. To illustrate her point, she contrasts it with the Tennyson quote and says that his "fierce light" (public scrutiny and criticism) no longer shines only upon the apex (the highest echelons of society) but upon the whole pyramid (underlings as well as their superiors).