Continuity mistake: When Tom starts beating the curtain with a book when he thinks he has captured Jerry, there is a chair behind him. There is no sign of the chair in the next shot, but when Jerry whacks Tom with a golf club, it is back again.
Continuity mistake: When Tom is about to drop the iron on Jerry, he is holding some cheese on a piece of string in his left hand. When the iron drops on Tom's foot, he is no longer holding the string.
Continuity mistake: When Jerry dives into the bottle of invisible ink, he dives in head first. When he emerges from the bottle, it is the bottom half of his body that is invisible first.