Dime Philadelphia

Is it a Philadelphia coin?

I have two Winged Liberty dimes and I can’t tell if they are Philadelphia coins or not. They look just like this http://typesets.wdfiles.com/local–files/merc-dime/merc_dime_obv.jpg Mine are ’44 and ’41. Is that “W” looking mark between the Y in LIBERTY and date, a mint mark or the initials of the designer? Are they for Philly?
I got a 1902 Barber dime also, where’s the mint mark location for that?

This link shows mint mark locations for US coins.

Ride For Dime Philly 2010 (The Ride)

Hubert’s Freaks: The Rare-Book Dealer, the Times Square Talker, and the Lost Photos of Diane Arbus $1.67 Bob Langmuir is an obsessive dealer with a remarkable eye for treasure who makes the discovery of a lifetime when he chances upon a trove of never-before-seen prints by the legendary Diane Arbus. From the moment he purchases a trunk containing the archive of Hubert’s Dime Museum and Flea Circus—a midcentury Times Square freak show frequented by Arbus—and discovers some intriguing photo…