In winter there is a considerable local trade in gravel and shingle, dug mainly in the valleys. Twenty years ago this trade was much more extensive in some districts than is at present the case; this being due partly to the exhaustion of the deposits, partly to the fact that in districts served by the Midland Railway the use of syenite from Mount Sorrel and Charnwood Forest, in Leicestershire, has to a considerable extent replaced flint-gravel as road-metal on the main highways of the county and in the metropolitan districts. Formerly, very large quantities of gravel were sent from St Albans and Harpenden to the northern metropolitan suburbs such as Hendon and Child’s Hill; but most of that now dug is employed for road-metal on the local by-roads. Here it should be mentioned that in Hertfordshire phraseology the term “gravel” is used exclusively to denote the coarse big-stoned material used as road-metal; what is ordinarily denoted as “gravel”--that is to say the material employed for garden-paths--being locally known as “hoggin.” Flints picked from the fields of the chalk area have a higher value as road-metal than dug gravel, owing to their superior hardness; the so-called “quarry-water,” which is present in all dug gravel, having been long since dried out. “Facing” flints for building purposes is an art much less commonly practised in the county than was the case in earlier days; and when buildings of faced flint are contemplated it is generally necessary to send to a distance in order to secure the services of an expert in the facing process. 14. History of Hertfordshire. The history of Hertfordshire includes such a number of events of primary importance that it is somewhat difficult to make a selection of those most fitted to appear in the limited space available. It was in this county that the offer of the crown of England was made to William the Conqueror, and it was from here that the first petition for the redress of grievances was forwarded to Charles I; while several important battles have been fought within its limits. To the two British tribes who inhabited this part of England previous to the Roman invasion, reference has been made in an earlier section. The first landing of Julius Caesar took place (in Kent) in 55 B.C., and the second and more successful in 54 B.C.; while a third Roman invasion took place under Claudius in 43 A.D., from which date the Roman legions held possession of the whole country till about the year 410 A.D. Whether Caesar himself ever visited Verulam does not appear to be definitely ascertained, but it was early in the history of that great city that the encounter between the British Queen Boadicea and the Romans took place. During the Roman period Hertfordshire, which then appears to have been a well-populated and wealthy district, formed a part of the province of Flavia Caesariensis. [Illustration: The Monastery Gateway, St Albans]