We are little Brethren twain,
Arbiters of Loss and Gain,
Many to our Counters run,
Some are made, and some undone.
But, Men find it to their Cost,
Few are made, but Numbers lost.
Tho' we play the, Tricks for ever,
Yet, they always hope, our Favour.

(highlight to see the answer)
answer: pair of dice

By Christina Rossetti
[first appeared in Sing-Song, A Nursery Rhyme Book (1872)]

Me you often meet
In London's crowded street,
And merry children's voices my resting-place proclaim.
Pictures and prose and verse
Compose me - I rehearse
Evil and good and folly, and call each by its name.

I make men glad, and I
Can bid their senses fly.
And festive echoes know me of Isis and Cam.
But give me to a friend,
And amity will end,
Though he may have the temper and meekness of a lamb.

My first is no proof of my second,
Though my second's a proof of the first.
If I were my whole, I should tell you
Quite freely my best and my worst.

One clue more:- If you fail to discover
My meaning, you're blind as a mole;
But if you frankly confess it,
You show yourself clearly my whole.

How many authors are my first!
And I shall be so too
Unless I finish speedily
That which I have to do.

My second is a lofty tree
And a delicious fruit;
This in the hot-house flourishes -
That amid rocks take root.

My whole is an immortal queen
Renowned in classic lore
Her a god won without her will,
And her a goddess bore.

There is one that has a head without an eye,
And there's one that has an eye without a head.
You may find the answer if you try;
And when all is said,
Half the answer hangs upon a thread.

(answer: Punch, punch)