Shrinking the size of my legend

Hi Folks!

I created a matplotlib bar chart containing 85 element. Now I'd like to
add a legend - but when I tired it this way:

plt.legend( (rect1[0], rect2[0],rect3[0]), ('1.00A_res_2.5tol',
'0.50A_res_1.5tol','0.25A_res_1.0tol') )

a huge legend legend covers large parts of my barchart.

Could anybody tell me how to shrink the entire legend to a smaller size?

Thanks alot!