جزییات کتاب
At the time of writing, virtually nothing had been published on the history of shield-work - the employment of a shield, with or without the aid of compressed air, in tunnelling operations of English origin. The author's aim was to gather in one volume a mass of information until then scattered and difficult to find. Abstract: At the time of writing, virtually nothing had been published on the history of shield-work - the employment of a shield, with or without the aid of compressed air, in tunnelling operations of English origin. The author's aim was to gather in one volume a mass of information until then scattered and difficult to find