Cuffed Slippers

[fiberfiction]

I'm knitting the Cuffed Slippers by Barbara Breiter. The pattern says to Repeat Rows 2 and 3 30 more times (16 ridges).
What is a "ridge"? Also, I repeated rows 2 and 3 30 more times (each row was knitted 30 times, alternately) and the slipper was ridiculously huge and used up nearly an entire skein of yarn. After working on this for two weeks I had to tear it back. Can anyone help me with this? I just want a slipper sock.