"The Wonderful Window" by Lord Dunsany

"The Book Of Wonder" was published in 1912. We don't know what time period this story was meant to be set in, so let's just use that date. 25s 6d in 1912 would be worth today, depending on what calculation you care to use, between £134 and £1,248. Which if we look up transom windows which might approximate that size (1'x2'), the low end of that price range isn't too far off from what you might expect to pay today. Maybe a bit high, but not completely off the charts insane high. Now the high end of that range would be insane for such a small window.... Of course, because this is a *magical* window, we probably should expect it to come in at the high end of the range.

Penates: in ancient Roman belief, household gods worshiped in conjunction with Vesta and the lares.

or / argent: heraldric terms for gold and silver, respectively. Note that while argent is technically silver, it was often in practice implemented as white. (And yellow was often used for or instead of gold.) But we have a most definite error here on Lord Dunsany's part, and one which given his own peerage he ought not to have made: in heraldry, metals were not placed upon metals. Obviously the Vatican, and the Kingdom of Jerusalem, did the or-on-argent thing, so it could be done, but those are pretty much the only examples you will find in all of history, so they are the proverbial exception that proves the rule. You won't find it anywhere else, and it ought not to have been done here, unless Dunsany is suggesting to us that the dominion in this story was actually a Papal dominion? But then who is the bear? Not Muslims - aside from the European country of Albania, animals are not a thing on the flags of Islamic countries. Who else would even be in a position to attack a Papal dominion that could possibly have a bear flag?

And yes, yes, there was once an imperial flag of China that was a white dragon on a yellow field (argent-on-or), I know. China was never bound by European heraldric laws :-P

jackdaw: a type of bird, similar to a crow or raven, but smaller.

The picture used is c.1400 – c.1416 Y Ddraig Aur (The Golden Dragon), royal standard of Owain Glyndŵr, Prince of Wales, famously raised over Caernarfon during the Battle of Tuthill in 1401 against the English. This particular depiction of the flag is by Rhŷn Williams and used here under the Creative Commons Attribution-ShareAlike 4.0 International license (https://creativecommons.org/licenses/by-sa/4.0/deed.en).

I know it's only one big gold dragon, not a lot of little gold dragons, but it's the only historical flag I could find that even remotely approximates the flag of interest to this story.

To follow along: https://www.gutenberg.org/files/7477/7477-h/7477-h.htm#THE_WONDERFUL_WINDOW