The British-English phrase to drop a brick means to commit a blunder, to make a tactless or indiscreet remark—cf. also to drop a clanger.
However, the earliest figurative uses that I have found of to drop a brick are of obscure meaning; the first is from A “Boarding” House, by Harford Worlock, a poem based on puns published in The Bystander (London) of Wednesday 16th June 1920 (the meaning of to make an ash too is obscure):
I’m fed up with these Housing schemes;
They’ve sold us all a pup with
Their “put up” jobs, although it seems
They’ve plenty to put up with!
What is “put up” is rent, and land,
And rates, and valuation.
And yet, in spite of the demand,
The concrete house is abstract, and
The “storeys” of the houses planned
Are quite without foundation!
So I intend to “plank” my cash
On wood, and if I feel
I’ve dropped a brick, and made an “ash,”
I’m building a good “deal”!
The architecture won’t be great,
But I shan’t be particular;
Byzantine would be more ornate,
But “Bythejoiner” (and his mate),
Will suit me if, at any rate,
The porch is “Perpendicular.”
Some recommend a roof that’s tarred;
I hate them, for they melt,
And when the rain is pouring hard,
It’s generally “felt”!
Others will recommend a style
Of corrugated plating,
Or else a neat encaustic tile,
But if my roof starts leaking while
I’m sleeping in my bedroom, I’ll
Give it a caustic slating!
And when my house, all “spruce,” and large,
With sawdust in the cracks,
Is finished, I suppose they’ll charge
Me then for Housing Tacks!
So I intend to squander first
The money that I’ve hoarded,
And spend it in a single burst
Upon my house, called “Chisel-hurst,”
Feeling that, at the very worst,
If I’m not lodged, I’m boarded!
The second-earliest instance that I have found of to drop a brick, also of obscure meaning, is from the personal column (i.e. the agony column) of The Times (London) of Friday 25th June 1920:
BRITISH OFFICER in the Tube, June 14th.—“I dropped a green god. Haven’t you, as you say, ‘dropped a brick’?”—America.
Among the other coded personal advertisements published in the same issue of The Times was this one:
CROAK like a raven: coo like a dove: blow hot: then cold: such characteristics belong to:—Sabina.
The meaning of to drop a brick is clearer in the following paragraph from The Reading Observer (Reading, Berkshire) of Saturday 3rd July 1920—interestingly, the author uses brick in the phrase as the ‘foundation’ of an additional metaphor:
One frequently hears the expression “an Englishman’s love of fair play,” but how often does one find it clogged by narrow-mindedness and red-tape. At a recent sports gala held in Palmer Park the consent of the Town Council was given to the sale of intoxicating liquor, and a similar concession was proposed by the Parks and Pleasure Grounds Committee in the case of the coming gala of the Comrades of the Great War. But, a deputation awaited on the Council and told them that it was the wish of the donor of the park that intoxicating liquor should not be sold there. In effect, and in vulgar terms, they said, “You have dropped a brick here.” So the Council went back upon themselves and refused the ex-service men’s application. Why make fish of one and fowl of another? Presumably because someone comes and tells them they have been naughty boys, and contravened a dead donor’s desire. If they “dropped a brick” on that occasion, then let them go on dropping similar bricks, and so build a foundation of fair play.
The phrase was used in one of the poems of The Skill Competition, in The Sportsman (London) of Saturday 9th February 1924; here, it is part of an extended metaphor based on the figurative use of to fall thick:
The following reply, published here recently, appears to have aroused a certain amount of feeling, judging by the tone of the further correspondence which follows. So many replies have been received that space can be given to a few only.
I’m a brindled dog of goodly form
That knows the way a hare to bear,
And, when feeling very fit indeed,
Can gallop at a decent speed
And course with every guile.
I am the dog appointed to
The laurel crown of which you tell,
My name, Good Sirs
—Tis Mah Boucaill,
Late of the Emerald Isle.
Preston Brook, Lancs.
What’s this I hear
About a Crown
And a brindled dog
To pretentious claims
I say Tut! Tut!
And subscribe myself
Yours truly, Mutt.
Where boast and brag
Is falling thick,
Excuse me if
I drop a brick.
The critics say
I’m led with ease,
I am the slow dog,
If you please.
But on the hare
I never fail,
The winner’s name
Is spelt Mardale.
The phrase appeared in two newspaper articles published on Friday 24th October 1924, during the first Labour government; both articles contrasted the Daily Herald, which supported the Labour Party, with the Daily Mail, a right-wing newspaper founded by Harold Sidney Harmsworth (1868-1940), 1st Viscount Rothermere, and his brother, Alfred Charles William Harmsworth (1865-1922), 1st Viscount Northcliffe.
The first of those articles is from The Mansfield Reporter and Sutton-in-Ashfield Times (Mansfield, Nottinghamshire):
Ald. John Marriott dropped a brick at the Labour meeting in the Y.M.C.A. Hall on Tuesday night, when he tried to say a good word for that Communist paper, the “Daily Herald,” but he finished up advising all of them to buy the “Daily Mail.” There was a little suppressed excitement on the platform, where the big wigs, looking very nice behind their huge red rosettes, sat, and a whispered tip to the alderman caused him to rise and apologise. He did not, he said, mean the “Daily Mail,” but the “Daily Herald.” There was a good deal of chuckling amongst the audience. It was quite a pardonable mistake, because the odds are Alderman Marriott sees the “Daily Mail” as frequently, or more so than the other publication which has no space for a good word for our own dear country, but can always find room for “copy” bolstering up the murderous Russian gang.
The other article appeared in the Daily Herald (London); the author conflated to drop a brick with the phrase to go (in) off the deep end, meaning to give way to emotion or anger (from deep end in the literal sense of the end of a swimming pool where the water is deepest):
Truth as to the Order to Men of the Navy
Once again the Rothermere Press has, so to speak, dropped a brick off the deep-end.
Yesterday the “Daily Mail” denounced as a “specially dirty” election method “borrowed from Moscow” and as an “outrageous interference with liberty” the alleged issuing by the Government this week of an order forbidding officers and men of the Navy to take part in the election.
The facts are these.
The old rule—waived because of the extraordinary circumstances of the 1918 election—prohibited either soldiers or sailors from electioneering.
It was restored, so far as the Army is concerned, in 1922, by the Coalition Government.
In the spring of this year the Admiralty decided that the same principle must be applied to both services.
That is all.
Our own view is that all Service men should have full political rights. But to talk of “dirty tricks” and “Moscow methods” is just hysteria. And hysteria is just—another straw which shows which way the wind is up.