There is surely still an appearance of separation between Xb and Yb, as if the one might slip off the other.
I have said nothing yet of the proportion of the height of Yb to its width, nor of that of Yb and Xb to each other.
Suppose we were to put a spur or prop to Xb at each corner, so as to hold it fast in the centre of Yb.
Under such circumstances, it is well to exhibit the lower tiers of the foundation as well as Yb and Xb.
But the limits of the height of Yb may be thus generally stated.
The three courses below are octagonal, with their sides set across the angles of the innermost octagon, Yb.
So does Adou's extraordinarily tall brother, Yb,—my guide among the mountains.
The symbol for the element ytterbium.
The symbol for ytterbium.
A soft, silvery-white metallic element of the lanthanide series that occurs as seven stable isotopes. It is used as a radiation source for portable x-ray machines. Atomic number 70; atomic weight 173.04; melting point 824°C; boiling point 1,196°C; specific gravity 6.972 or 6.54 (25°C) depending on allotropic form; valence 2, 3. See Periodic Table.