This is kind of a special ICFBN. Sure, the free e-books and old-timey baseball annuals are nice, but did you know that video existed of Walter Johnson pitching? I didn't. Probably should have figured it out considering when moving pictures came to be, but here you go.
And, by law, I'm required to GIF one of those clips. Okay, two.

That's a good view of his general delivery, but I think this one gives you a great idea of his deception:

I had no idea he threw sidearm, though I guess I could have read this book and got this quote from William B. Hanna in Baseball Magazine from 1923:
The great Washington pitcher is a side-arm thrower, long of arm, strong in control, and pitches with as little visible effort as anybody I've seen expect Jack Powell.
Look at how late the ball comes out of the hand. Assuming he threw over 90 m.p.h. (which he almost certainly did), he could probably still fit in a modern bullpen.
Previous Internet Christmases
I: 1930 Spalding Base Ball Guide II: Negro Leagues Database
III: Bob Gibson video
IV: John McGraw's Scientific Baseball
V: NBC Archive, featuring Bud Selig
VI: 1888's Base-ball: How to Become a Player VII: Connie Mack's How To Play Base-Ball
VIII: Life Magazine's greatest baseball photosIX: Branch Rickey's scouting report on Don DrysdaleX: 100,000+ crowd for White Autos game
XI: Thomas Edison baseball videoXII: Babe Ruth in Just PalsXIII: Stories of the Base Ball FieldXIV: Babe Ruth swing analysisXV: Bob Feller mechanical analysis
XVI: Vin Scully calling Hank Aaron's 715th home runXVII: 1934 Tigers/Yankees Radio BroadcastXIX: Bob Feller's fastball racing a motorcycleXX: PCL Promo video from 1946 XXI: Oakland Oaks parade
XXII: Old-timey Red Sox picture collection
XXIII: A visual history of Seals Stadium
XXIV: Baseball Reliquary Online Museum
XXV: Proto-snark from 1915
XXVI: The 1924 Nationals and the Washington Post
XXVII: Before there was GameDay or the Internet ...
XXVIII: Glorious collection of old-timey radio broadcasts
XXIX: Free Bill Veeck eBook
XXX: Jackie Robinson photos from Ebony