TunnelingNote 16 — Chapter XXV · THE COST OF TUNNEL EXCAVATION AND THE TIME REQUIRED FOR THE WORK.Reading editionAre unlined.◇[17] Lined with timber.◇Copy noteReturn to CHAPTER XXV. THE COST OF TUNNEL EXCAVATION AND THE TIME REQUIRED FOR THE WORK.Return to CHAPTER XXV. THE COST OF TUNNEL EXCAVATION AND THE TIME REQUIRED FOR THE WORK.Return to CHAPTER XXV. THE COST OF TUNNEL EXCAVATION AND THE TIME REQUIRED FOR THE WORK.