The two main devices (symbols) in the Bostock blazon are the fesse hummette and helmet. The two main tinctures (colors) are sable and argent.
Sable, the deep black so often found in Heraldry is believed to named from an animal of the marten family know in the middle ages as a Sabellinœ and noted for its very black fur 1A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:Sable. In engravings, when colors cannot be shown it is represented as closely spaced horizontal and vertical lines, and appropriately is thus the darkest form of hatching, as this method is known 2Boutell’s Heraldry, J.P. Brooke-Little, Warne, (revised Edition) London 1970, P 26. Although it may seem a sombre tone, and does indeed sometimes denote grief, it is more commonly said to represent Constancy 3The Symbolisms of Heraldry, W. Cecil Wade, George Redway, London, 1898 P35.
Argent is the heraldic metal Silver and is usually shown as very pure white. It is also known more poetically as pearl, moon (or luna) 4Understanding Signs & Symbols – Heraldry, S. Oliver & G. Croton, Quantum, London, 2013, P53. In a sketch or drawing it is represented by plain, unmarked paper 5A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1847, P11.
The fesse is a broad horizontal band across the centre of the shield, in very ancient times it was said to occupy one third of the area height of the shield 6A Complete Guide to Heraldry, A.C. Fox-Davies, Bonanza (re-print of 1909 Edition), New York, 1978, P117, however it soon became somewhat narrower. This created an opportunity to add decorative edging to the band, of many forms, and to very pleasing artisitic effect, at least close up – it must be admitted that at distance some of the forms are hard to distinguish! Humettee is a word of uncertain origin that means couped or cut. It is applied to so-called ordinaries, the large features that typically extend across the whole of the field, but their description as humettee means that, whilst still occupying the bulk of the space, they are cut short before reaching the edge 7A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:Humetty.
We should not be surprised to find items of armour depicted on shields, and perhaps to the wearer none is more important that the helmet. Wade suggests that its presence denotes “Wisdom and surety in defence”. 8The Symbolisms of Heraldry, W. Cecil Wade, George Redway, London, 1898 P139 There are many variations of helmet described, now almost indistinguishable to modern eyes, and not having any particular significance – perhaps because of some play on words with the family name. There are complex heraldic rules and guidelines for the depictions of helmets belonging to various grades of nobility, lack of space prevents us from listing them all here!9A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:helmet