Augmentation, or augmentation of honor, is a term describing the addition to a coat of arms at a later date to the original granting of the arms. This augmentation is usually granted by a sovereign to commemorate worthy or illustrious deeds. These augmentations usually take the form of an escutcheon ( a smaller shield within the arms), a canton ( a square in the top left of the arms), or an additional charge to the arms.
While most augmentations are simple as in the example above, there are also examples of over the top additions to arms such as that of the arms of Ross, image above. The original arms, Gules three estoiles in chevron between as many lions rampant argent was changed with the addition of a chief containing a portion of a globe of the earth, the globe is positioned exactly as the place of the magnetic pole in latitude 70°5'17'', and longitude 96°46'45'', west. There are two crests, one of which is a rock with a flagstaff flying the union jack inscribed with the date June 1st 1831, when the magnetic pole was discovered by Sir John Ross. After the augmentation the following was the new blazon of arms, far from simple !
Gules, three estoiles in chevron between as many lions rampant Argent;
[for augmentation] a chief Or, thereon a portion of the terrestrial globe Proper, the true meridian described thereon by a line passing from north to south Sable, with the arctic circle Azure; within which the place of the magnetic pole in latitude 70°5'17'', and longitude 96°46'45'', west, designated by an inescutcheon Gules, charged with a lion passant gardant of the First; the magnetic meridian shewn by line of the Fourth passing through the inescutcheon with a correspondent circle, also Gules, to denote more particularly the said place of the magnetic pole; the words following inscribed on the chief, viz., "Arctæos Numine Fines".
Crest: Two helms.
Dexter: Over a downward pointing floating compass the Union Jack inscribed "1st June 1831" fesswise.
Sinister: A fox's head erased proper [for "Ross"].
Motto: Spes Aspera Levat -- " hope lightens difficulties"