Mechanical and Technical Processes. Materials 141
transport of stone, which he records was made from acacia-
wood and measured 60 cubits (103 feet) in length, and 30 cubits
(51 feet 6 inches) in width, and which was constructed in 17
days. This would seem almost an impossibility if the construc-
tion were like that described by Herodotus or shown on the
Lisht boats. On the other hand, a raft of logs could easily have
been made in the time.
FIG. 18. IVth-Dynasty ship under full sail from the tomb of Ipi at Saqqara.
Now in the Cairo Museum.
Sails were of rectangular form, and the halyards did not
pass through pulleys but either through holes pierced in the
mast, rectangular frames lashed to the mast, or rings attached
to the mast (Fig. 18); these devices would cause very great
friction when the halyards were pulled. A feature of most
Egyptian sailing-boats is the seemingly unnecessary number
of ropes which hold up the lower yards. My explanation of
them is that, lacking pulleys, the Egyptian crew had to