Reference for Rosh Hashanah 2:3
כֵּיצַד הָיוּ מַשִּׂיאִין מַשּׂוּאוֹת, מְבִיאִין כְּלֻנְסָאוֹת שֶׁל אֶרֶז אֲרֻכִּין וְקָנִים וַעֲצֵי שֶׁמֶן וּנְעֹרֶת שֶׁל פִּשְׁתָּן וְכוֹרֵךְ בִּמְשִׁיחָה, וְעוֹלֶה לְרֹאשׁ הָהָר וּמַצִּית בָּהֶן אֶת הָאוּר, וּמוֹלִיךְ וּמֵבִיא וּמַעֲלֶה וּמוֹרִיד, עַד שֶׁהוּא רוֹאֶה אֶת חֲבֵרוֹ שֶׁהוּא עוֹשֶׂה כֵן בְּרֹאשׁ הָהָר הַשֵּׁנִי, וְכֵן בְּרֹאשׁ הָהָר הַשְּׁלִישִׁי:
How did they light the beacons? They brought long cedar beams [which would be seen from afar], and reeds, and oil-wood, and hatchelled flax [to increase the flame], and one would tie them all together with a rope and go up to the top of the mountain and light it, and move it from side to side and up and down until he saw his friend (i.e., his counterpart) doing so on top of the second mountain; and so, on top of the third mountain, etc.