Burke's General Armory says:
Blackburne (Orford and Hale, co. Lancaster). Ar. a fesse nebulae betw. three mullets sa., quartering Norbis, Leveb, AsHTON, Green, Aspenwall, Ireland, Hutt, Hesketh,
Holland, Columbers, Walton, Merton, Bebbington, Handford, Praers, Birkenhead, Huoheslt, Done, Kingslet, and Stretch.
Crest—A cock ppr. standing upon a trumpet or.
The trumpet would be of the post-horn style, or as used by the military.
"ppr" means proper - i.e. in natural colours.