Has anyone done the research to figure out why Adolphe decided to create instruments tuned to Eb and Bb? Why not C? Was he trying to match Bb brass instruments? Why not F like the French Horn?
It makes you go hmm...
cann0nba11, Dave is right, no-one has really answered your question, so I'll try - although there are loads of internet sources, but some are like wading thro' treacle... I already mentioned he did produce a C Bass as his first sax. It's also obvious that to produce a complete range of saxophones with the same fingering, when just having them an octave apart in C would only make a handfull - you have several different keys, as is also the case with clarinets etc.
To quote from several internet sources - Adolphe Sax patented the saxophone in France on June 28, 1846. The patent was for a period of fifteen years. The patent covered two groups of instruments with a total of 14. They were the E flat sopranino, F sopranino, B flat soprano, C soprano, E flat alto, F alto, B flat tenor, C tenor, E flat baritone, B flat bass, C bass, E flat contrabass, and F contrabass. Each instrument was of a different size. One group of seven was pitched alternatively in F and C, for orchestral use. The other group of seven was pitched in E-Flat and B-Flat for military band use.
Whether, in hindsight, it's sensible to say "OK, we'll change the pitch of the saxes, but, whatever instrument we play, all 3 left hand fingers make (for us) a G", or just to leave us to remember where the concert notes are on each differently pitched horn, and learn the notes by their concert pitch, is a matter for debate. I prefer the former argument.
C and F seems natural for orchestra, and I hope some historian will confirm that the stranger Bb/Eb keys were influenced by the existence of Bb trumpets etc. in marching bands, so it was just keeping to some (almost) multi-standard ? I seem to remember reading somewhere that in tests, one pitch produced the most 'robust' sound of all, with most resonance, Bb maybe ?
Don't forget, this was at a time when orchestral horn players carried a bag of differently pitched tuning slides, to have a wide variety of natural keys available on their horns by just changing the slide. Enter the Ophecleide, eh hakukani, got one yet ?
The rest is history, as I said before, orchestral use was limited, band use grew amazingly, so the C/F's died, and the Bb/Eb's flourished.... Except for a short C revival in the 20's.
So, in answer to your question, he originally decided to create them in a multitude of keys, not just Bb/Eb. And, although his first 'production' sax was the bass in C, who knows what his very first thought was ? All I know is, that I'm glad Adolphe Sax didn't wake up one overcast morning, and decide that his new inventions should be pitched in Db and Gb !
OK, all you historians - rip it to shreds.....
P.S. - just seen Gary's five-word answer.... I started typing long before that