of Totenkirchl, Austria, UIAA Grade V (5.7 with a tension traverse) 19 pitches. 1909 : (approximately) Felt-soled rock climbing shoes are introduced. 1910s 1910 : replaces the attached ring on pitons with an eye in the body of the piton, a design still used to this day. 1910 : designs and utilizes a stronger, user-friendly, steel carabiner, specifically made for tension traverses with modern pitons. 1910 : , Oliver Perry-Smith, and H. Wagner ascend the Großer Falknerturm on Matthäusriß, in the Saxon Switzerland climbing region, Sax VIIb, maybe the first . 1910 : leads Südriss on Kreuzturm, in the Saxon Switzerland climbing region, Sax VIIc, and hardest short climb for a decade, the first-ever . 1910 : Angelo Dibona, G. Mayer, M. Mayer, A. Dimai, L. Rizzi climb the 2,500-foot North Face of , in the Dolomites, UIAA V+ (5.8). 1910 : Franz Schroffenegger and Franz Wenter climb the 450-metre Northwest Face of Delago Tower, and the 500-metre North Face of Croda di Re Laurino, in the Dolomites. UIAA Grade VI- (5.9-). 1911 : Paul Preuss free soloed the first ascent of the 900-foot East Face of Campanile Basso, in the Italian Dolomites, on friable rock. 1911 : September, Paul Preuss, starts the Mauerhakenstreit (piton dispute) and advocates for a transition to free climbing; in a series of essays and articles in the German Alpine Journal, he defines "artificial aid" and proposes 6 rules of free climbing including the important rule 4: "The piton is an emergency aid and not the basis of a system of mountaineering". 1912 : Angelo Dibona, Luigi Rizzi, and brothers Guido and Max Mayer, climb the South Face of the Meije, in the Massif des Écrins, France. 1913 : Hans Dülfer free soloed, onsight, the 250-metre Dülferriss on the Fleischbank, in Austria, at UIAA VI- (5.9-) (6-pitches). 1913 : Hans Dülfer and Willi von Redwitz, climb the 700-metre West Face Direct, on Totenkirchl, in Austria, at UIAA V+ (5.8 X), in 8 hours (23-pitches, longest rock climb to date). 1913 : Hans Dülfer, with only 3 pitons, leads the West Face Cima Grande, in the Dolomites, at 5.8 X (8-pitches); he invents a 5-step grading system, the rope tension traverse, and dülfersitz rappelling. 1913 : Rudolf Fehrmann publishes the second edition of Der Bergsteiger in der Sächsischen Schweiz (The Climber in Saxon Switzerland), which includes the first binding rules for climbing in the area to