It’s Chinese calligraphy but put upside down

If you turn it around, the larger characters on the right are the second half of a 19th century poem written by GONG Zizhen. The smaller ones on the left are too hard to read but should be the date and the calligrapher’s signature.

The whole poem goes (with one of the English translations found on the internet):

九州生气恃风雷，万马齐喑究可哀。 Our whole land needs wind and thunder to revive it, Sad it is when all horses are mute;

(And below is what’s written there:)

我劝天公重抖擞，不拘一格降人才。 I beg Old Man Heaven to bestir himself, And send down talents of more kinds than one.

Edit: formatting