A while ago I discovered that the Singer's Prayer Book editorship made quite a lot of tweaks to subsequent early impressions of the first edition. I'm intrigued to know how the earliest impressions were different from the late first edition (from the 1950s) that my father has, and have been keeping my eye out for a few years for early impressions online. Unfortunately, truly early ones (pre-1895, or for that matter even pre-1900) don't seem to be turning up. When I had another look a few days ago and found the 1904 impression scanned and readable online, I thought this was probably going to be as good as I was going to get, and I had a look through this volume to see what it offered.
(I'm aware that most of my readership to whom this would be meaningful will be reading from Facebook, not LJ or DW; but I'm posting it here anyway, so that I can find it again afterwards.)
The early impressions, 1904 included, made much use of references to save page-count (to keep the price down to 1/–), something that was eliminated in subsequent volumes but without retypesetting the complete book; hence the joke: How can you tell someone who uses the first edition Singer's siddur? Get them to count to one hundred and see if they go 94, 94a, 94b, 94c etc. In the 1904 impression mincha consists of a list of references to prayers found elsewhere, and takes up a single page, expanded in later impressions to no fewer than fifteen pages.
Tallis and tefillin are to be donned after, rather than before, ברכת השחר.
No Kaddish deRabbanan after ברכת השחר or, later on, פִּטּוּם הַקְּטוֹרֶת. (Even the second edition (1962) merely says some congregations recite it there.) This kaddish is included in the 1904 impression after Shacharis with the legend "Kaddish to be said after reading Lessons from the Works of the Rabbis".
מזמור שיר חנוכת הבית לדוד is found after Shacharis, with the label "In some Congregations the following Psalm is said daily before ברוך שאמר". The subsequent Mourner's Kaddish is missing altogether.
ויברך דויד is only said standing until משתחוים.
In ובא לציון and elsewhere Aramaic is described instead as "Chaldee".
No עלינו or subsequent kaddish in mincha on Friday. (The idea, so I've heard, is that these are both recited at the end of the service, and when services are recited back-to-back, you're not really ending it. We still do this between mincha and ne`ila on Yom Kippur.)
No meditation before kindling the Shabbos lights.
No Mourner's Kaddish after במה מדליקין. (This was also the case in the second edition.)
A little to my surprise, וְדִי בְּכָל אַרְעָת גַלְוָתָנָא "and in all the lands of our dispersion" is already added to the first יְקוּם פָּרְקָן in this edition. (This is one of the rare cases of an Orthodox authority tweaking the traditional wording of a prayer; the rest of the Orthodox world (e.g. ArtScroll) still has here "in Israel and in Babylonia" and expects the reader to infer the rest of the world as well.)
The Prayer for the Royal Family is somewhere I was expecting change; over the years the wording of the mediaeval prayer הַנּוֹתֵן תְּשׁוּעָה לַמְּלָכִים. was gradually shortened. (Of course, that prayer was written about absolute monarchs, which is why my (non-Orthodox) shul in London replaced it with a prayer for the government, not one for the Queen with a single short reference to the government ("her counsellors").) The wording given here, with changes compared to the second edition in bold, reads:
He who giveth salvation unto kings and dominion unto princes, whose kingdom is an everlasting kingdom, who delivered his servant David from the hurtful sword, who maketh a way in the sea and a path in the mighty waters,—may he bless, guard, protect and help, exalt, magnify, and highly aggrandize [in the Hebrew only, redundantly repeating the following words: אֲדוֹנֵינוּ הַמֶּלֶךְ] our Sovereign Lord, King Edward, our gracious Queen Alexandra, George Prince of Wales, the Princess of Wales, and all the Royal Family [in the Hebrew only: יָרום הוֹדָם may their glory be exalted].
May the supreme King of kings in his mercy preserve the King in life, guard him and deliver him from all trouble, sorrow and hurt. May he make his enemies fall before him; and in whatsoever he undertaketh may he prosper. May the supreme King of Kings in his mercy put a spirit of wisdom and understanding into his heart and into the hearts of all his counsellors, that they may uphold the peace of the realm, advance the welfare of the nation, and deal kindly and truly with all Israel. In his days and in ours, may Judah be saved, and Israel dwell securely [missing here: the text of the second edition, and probably also later impressions of the first edition, is missing altogether: "may our Heavenly Father spread the tabernacle of peace over all the dwellers on earth"]; and may the redeemer come unto Zion. O that this may be his will, and let us say, Amen.
No Prayer for the State of Israel, of course, as it didn't exist yet.
Duchaning is, surprisingly, missing.
The traditional wording for מָעוֹז צוּר is given. (Chief Rabbi Hertz later changed לְעֵת תָּכִין מַטְבֵחַ מִצָּר הַמְּנַבֵחַ "when thou shalt have prepared a slaughter of the blaspheming foe" to לְעֵת תַּשְׁבִּית מַטְבֵחַ וְצָר הַמְּנַבֵחַ "when you have caused the slaughter to cease, and the barking of the enemy" [translation by myself], but it was changed back in the second edition.) דְּבִיר, which I would translate "shrine", and designates part of the Temple, is translated here as "oracle".
The four verses after the psalm before bentshing on Shabbos and yomtov are not given. (Only the first two are there in the second edition.)
Psalm 150 to be recited at the end of the wedding service. (Also in the second edition; reduced to "Some congregations" in the third.)
At the end of the last page, the end. :o) Total page count: 660, as against 841 in the second edition, 903 in the third and 926 in the fourth.