rst of all ascertains , by measuring in the manner which I have explained above , which part of the tunnel or drift lies beneath the surface boundary mark , stretching the cords along the drifts to a point beyond that spot in the rock where he judges the mark should be cut . Then , after the same… … INSTRUMENT . B — ITS TONGUE . C , D , E — HOLES IN THE TONGUE .
e-rara · Eisenbibliothek Schlatt · No known copyright restrictions. Free to use for anything.
![An illustration from Recreations in science and natural philosophy: Dr. Hutton's translation of Montucla's edition of Ozanam [electronic resource] (1844)](https://img.insideoutlibrary.com/img/200/ia-b21307507-542-0.webp)
![An illustration from [Electric engineering.] (1902)](https://img.insideoutlibrary.com/img/200/ia-electricengineer01inte-164-66.webp)
