Images from Google:

http://www.royal-park.com/graphics/careerwear/four-in-hand/four_in-hand2.gif


http://www.how-to-tie-a-necktie-knot.com/images/knots/4inHand_tie_knot_step4.jpg

So, wwh, I don't think the four-in-hand is now considered to be a bowtie; however, perhaps it was back in O'Henry's time.

And, to further this little adventure, why is this particular four-in-hand method of tying a necktie called a
'four-in-hand' knot?