How to globally change the fonts properties ?

Hi again,

I find that all the fonts on my figures are too large ; up to now I've been
modifying some of them using:

   from matplotlib.font_manager import FontProperties
   small=FontProperties( size="small" )

but there are still some fonts, e.g. on the ticks of the colorbars, that I
couldn't figure out how to change ; anyway a better option, which would lead
to less verbose commands, would be to specify default font properties for all
the text of the figure.

Is there a way of doing it ?

Thanks in advance,