What was left alone

The brief was to fix scanning artifacts and leave the author's wording, spelling and punctuation untouched. That distinction is the most consequential judgment in the whole job, so this file records where the line was drawn and why.

How the two were told apart

OCR errors and typing errors fail in different ways, and the difference is usually legible:

Scanning errors are visual. Tesseract confuses letters that look alike at 300 dpi on a worn typewriter ribbon — n/h, l/1, i/l, v/y, c/e, rn/m, q/g. So tne for the, nad for had, inguiry for inquiry, 3lst for 31st. These produce strings no typist would ever produce, and they appear once or twice rather than consistently.

Typing errors are phonetic or mechanical — a doubled letter, a dropped letter, a transposition, a misremembered spelling. So occured, embarassment, accomodated. These recur, because a writer who spells a word one way tends to keep spelling it that way.

Where the two tests disagreed, or where a reading could plausibly be either, the page image was opened and the question settled by looking. Anything still ambiguous after that was left as scanned, on the principle that an unwanted authorial quirk is recoverable later but an invented word is not.

Consistent authorial spellings

Each of these appears in the typescript as written, most of them more than once:

Spelling	Times	Standard form
occured	7	occurred
socalled	3	so-called
longitudenal	4	longitudinal
anonimity	3	anonymity
darkeness	3	darkness
embarassment	3	embarrassment
dilemna	2	dilemma
disasterous	2	disastrous
reconaissance	2	reconnaissance
selfassurance	2	self-assurance
accomodated, accomodations	1 each	accommodated / accommodations
aeronatical	1	aeronautical
aggrevated	1	aggravated
appearence	1	appearance
assesment	1	assessment
assidiously	1	assiduously
battallions	1	battalions
boyancy	1	buoyancy
brakish	1	brackish
capablities	1	capabilities
caried	1	carried
combattants	1	combatants
concesssion	1	concession
condtions	1	conditions
consitute	1	constitute
envisionaged	1	envisaged
Penninsula	1	Peninsula
propellors	4	propellers
Portugese	12	Portuguese

One-off typing slips, kept

Verified against the page image in each case — the typescript reads this way:

Page (scan)	Reading	Standard form
25	mililtary airships	military
150	43 degress F.	degrees — and degrees is spelled correctly on the very next line
155	broke through the clounds	clouds
155	and alkso from the altimetric record	also
187	the Bulgartian recruits	Bulgarian — spelled correctly in the same sentence
146	allowing for necessary parations	preparations
253	seems to have been into circulation	put is simply missing
166	Wichester grand jury	Winchester
—	Dartmout and others	Dartmouth
—	Shorly after May 17	Shortly
—	snow-capped Kililmanjaro	Kilimanjaro
—	Mirable dictu	Mirabile dictu
—	the House of Hohenzoller	Hohenzollern
—	An Imperial Commenddation	Commendation
—	Straser sent a telegraph	Strasser — correct in dozens of other places
—	Feburary 1919	February
—	Admiral Tripitz	Tirpitz
—	a station at Kamina in Germanland	German land
—	for the Mediterraenean area	Mediterranean
—	Commander Mangelsdorff	Mangelsdorf — the author uses both
—	the airship portection	protection
—	gradully tiring, a surpise attack, it could be troubleseome	gradually / surprise / troublesome
—	the sailors weren restless	were
—	interrested in whether	interested
—	the avalable information, radion triangulation	available / radio
—	explosion of gas, ammuntion and fuel	ammunition
—	as Sir Alfred had descibed it	described
—	To guard minsweepers	minesweepers
—	had probably suceeded	succeeded
—	Weather and cicumstances	circumstances
—	lay wainting in its hangar	waiting
—	whatever suppplies it contained	supplies
—	ropute provided for in the original plan	route
—	With alighter ship	a lighter
—	enough metereological information	meteorological — he also writes meterological
—	a factually corect account of the voyage	correct
—	may have acounted for this	accounted
—	unable to develope them	develop
—	firsat at the destruction	first
—	across terrestial obstacles	terrestrial
—	parabaloid shaped	paraboloid

That list is longer than the corrections log's letter-confusion section, and deliberately so. It is the clearest evidence that the transcription is faithful: after the scanning errors were removed, what remained was a writer's own typing.

British spellings

Left as typed rather than Americanised: criticised, emphasise, cyphers, and judgement — though the author is inconsistent here, using judgment 14 times against judgement 3 times. Both forms are his, so both stand.

The author's compound nouns

He habitually closes up compounds that most writers hyphenate or space. These are a stylistic habit, not errors, and they are consistent:

airforce · airforces · airdefense · airwar · airmasses · airlayers · airlegs · airstrength · airshipmen · groundcrew · bombload · machinegun · machineguns · rudderman · wingracks · teaparty · duraluminum

German and French left in place

von · der · des · Jetzt erst recht! · Der Feind hört mit! · vertretbare Schuld · Faust Natur · Hochwohlgeboren · Spähkorb · Reichsmarineamt · Admiralstab · Aktiengesellschaft · Afrika zu unseren Füssen · Zeppelin flieg. · Hilf uns im Krieg. · Quai d'Orsay · Deuxième Bureau · Pour le Mérite · lingua franca · askaris · elan

Umlauts were restored in these, because the scanner had mangled the diacritic itself into &, é, S or 8 — that is a scanning failure, not a spelling choice. See section 1 of corrections.md.

What remains uncorrected

About 0.46% of words in the finished document are not in a standard English dictionary. A large share is the material above — authorial spellings, German, and proper nouns from the manuscript's cast of several hundred people, ships and places. The remainder is a thin tail of single-occurrence OCR slips on faint lines that were judged not worth the risk of a guess. If you want to work through them, pipeline/tools/review_residue.py regenerates the review sheets that pair each remaining oddity with a crop of the line it came from.