The two main devices (symbols) in the Priestley blazon are the tower and grappling iron. The two main tinctures (colors) are gules and ermine.
The bold red colour on a heraldic shield is known as gules. It has a long history within heraldry, it is known that one of those who besieged the scottish castle of Carlaverock in 1300 was the French knight Euremions de la Brette who had as his arms a simple red shield.1The Siege of Carlaverock, N. Harris, Nichols & Son, London, 1828, P180. The word gules is thought to come from the Arabic gule, or “red rose” 2Boutell’s Heraldry, J.P. Brooke-Little, Warne, (revised Edition) London 1970, P 313. Later writers associated it with the precious stone ruby and the metal iron 3Understanding Signs & Symbols – Heraldry, S. Oliver & G. Croton, Quantum, London, 2013, P53, perhaps because of the red glow of iron in the heat of the blacksmith’s forge.
Ermine is a very ancient pattern, and distinctive to observe. It was borne alone by John de Monfort, the Earl of Richmond and Duke of Brittany in the late 14th century 4A Complete Guide to Heraldry, A.C. Fox-Davies, Bonanza (re-print of 1909 Edition), New York, 1978, P69 It has a long association with royalty and the nobility in general and hence represents “Dignity” wherever it is found 5The Symbolisms of Heraldry, W. Cecil Wade, George Redway, London, 1898 P39. The ermine pattern is white with, typically, a three dots and a dart grouping representing the tail of the furred creature.6Boutell’s Heraldry, J.P. Brooke-Little, Warne, (revised Edition) London 1970, P 28. The ermine spot is sometimes found alone as a special charge on the shield.
Architectural items, from individual components to entire buildings 7Boutell’s Heraldry, J.P. Brooke-Little, Warne, (revised Edition) London 1970, P 92 feature frequently as charges In a coat of arms. Not surprisingly, considering the times from which many arms date, fortifications are common. The tower Is a typical example of an object from the world of architecture adopted, albeit in a stylised form, for use in heraldry. It can be placed alone, or frequently with three turrets on the top, known as a tower triple towered, and can have doors and windows of a different colour. 8A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:Tower In continental European heraldry they are often accompanied by pictorial effects such as armoured knights scaling them on ladders.
Given the martial nature of the origins of Heraldry, in the identification of knights and men-at-arms it can come as no surprise that mediaeval weaponry of all types are frequently to be found in a coat of arms 9Boutell’s Heraldry, J.P. Brooke-Little, Warne, (revised Edition) London 1970, P 89. The grappling iron resembles a set of large hooks, familiar to use from many a castle siege in the movies! Its meaning needs little explanation beyond its military nature.