Sauropod Vertebra Picture of the Week

It turns out that G. K. Chesterton conveniently summarised all of my advice on slide preparation more than a century ago:

This is the sort of [slides] we like
(For you and I are very small),
With pictures stuck in anyhow,
And hardly any words at all.

You will not understand a word
Of all the words, including mine;
Never you trouble; you can see,
And all directness is divine.

Stand up and keep your childishness:
Read all the pedants’ screeds and strictures;
But don’t believe in anything
       That can’t be told in coloured pictures.

(Inscribed in the front of a child’s picture book, around 1906.)