Dr. Slop is using Toby as a guinea pig, attempting to demonstrate how the forceps work. Poor Toby holds his hands wrong and gets some skin ripped off.
Mr. Shandy interrupts that it was a good thing that Dr. Slop wasn't operating on the baby's head just then, or else you could say sayonara to little Tristram. Dr. Slop insists that he could have extracted him by the feet.
But the midwife doesn't think so—she's pretty sure that the baby is coming out head down.