Series 13

E1. Coils and Springs

Jan 1, 1974

E2. Opposites

Jan 8, 1974

E3. Signs and Signals

Jan 15, 1974

E4. Ghosties and Ghoulies

Jan 22, 1974

E5. Triangles

Jan 29, 1974 · 25m

E6. Waves

Feb 5, 1974 · 25m

E7. Food

Feb 12, 1974

E8. Windows

Feb 19, 1974

E9. Drips and Drops

Feb 26, 1974 · 25m

E10. Humps and Lumps

Mar 5, 1974 · 25m

E11. Air

Mar 12, 1974

E12. Growing

Mar 19, 1974 · 25m

E13. Bags

Mar 26, 1974

E14. Spikes

Apr 2, 1974 · 25m

E15. Episode 15

Apr 9, 1974

E16. Circles

Apr 16, 1974 · 25m

E17. Reflections

Dec 31, 1974 · 25m

E18. Episode 18

Jan 14, 1975

E19. Episode 19

Jan 21, 1975

E20. Episode 20

Jan 28, 1975

E21. Building

Feb 4, 1975 · 25m

E22. Episode 22

Feb 11, 1975

E23. Space

Feb 18, 1975 · 25m

E24. Games

Feb 25, 1975 · 25m

E25. Episode 25

Mar 4, 1975

E26. Episode 26

Mar 11, 1975

E27. Episode 27

Mar 18, 1975

E28. Dark and Light

Mar 25, 1975 · 25m

E29. Litter

Apr 1, 1975 · 25m

E30. Zigzags

Apr 8, 1975 · 25m