Such verses are called Spondaic.
"New Latin Grammar" by Charles E. Bennett
No English poem is entirely spondaic.
"English: Composition and Literature" by W. F. (William Franklin) Webster
The spondaic lines convey that of slowness.
"Graham's Magazine Vol XXXII No. 1 January 1848" by Various
There is in its slow spondaic movement an eternity of tears.
"Robert Burns" by Gabriel Setoun