July 12, 1952: Charlie Brown is bi-lingual

Snoopy can say "Arf." So, apparently, can Charlie Brown, even though he isn't a native speaker.

Sunday, July 6, 1952: Group picture

Lucy still has her round eyes (which look even weirder than usual in the second panel). Snoopy says "Shh!" And it's another turnabout/chase strip, demonstrating that, while Charlie Brown has been seeming depressed lately, he's still got a lot of his old self in there.

April 28, 1952: Adult word-balloon!

Schulz probably used one of these rarely-seen adult-spoken word balloons due to the difficulties in depicting muted trumpet on the comics page.

Lucy's eyes are growing out of their wide-circled phase slowly.

New Year's Day, 1952 : I think I see why Patty hates Charlie Brown now

I think Patty is fully due that Scribble Of Ire in the last panel.

December 29, 1951: Where did he get tinder?

The icicle-dripping word balloon in the second panel is nice.

Let's talk for a moment about the Peanuts characters' repertoire of expressions.

1. Neutral: No mouth at all when viewed in profile, a small dot or dash when viewed from the front

2. Mild Surprise/Interest: Neutral, but with small, upside-down-U eyebrows over the eyes. See Violet in panel four here.

3. Happy: Triangular mouth in profile, standard smile from the front or a faked profile triangle.

4. Angry: Eyebrows drawn as one long line from the front ("unibrow"), diagonal eyebrows going down towards nose when viewed in profile. Mouth is Neutral if mild anger, or a horizontal line if stronger.

5. Worried: Similar to Angry, but with slanted eyebrows arcing up at the nose line. Also, no unibrow. Mouth as in Neutral. Charlie Brown in all frames here, also Violet in panel three.