According to Hugh Nibley, for some it might be perplexing that the reference in Ether 2:23 to "windows . . . [that] will be dashed in pieces seems to refer to glass windows, since no other kind would be waterproof and still be windows, and the windows would have to be brittle enough in order to be dashed "in pieces." Moreover, Moroni, in actually referring to "transparent glass" in Ether 3:1, is probably following the words of Ether.
This would make the invention of glass far older than anyone dreamed it was until the recent finding of such objects as Egyptian glass beads from "the end of the third millennium B.C." Nevertheless, "very little . . is known," writes Newberry, "about the early history of glass," though that history "can indeed be traced back to prehistoric times, for glass beads have been found in prehistoric graves." We need not be surprised if the occurrences of glass objects before the sixteenth century B.C. "are few and far between," for glass rots, like wood, and it is a wonder that any of it at all survives from remote antiquity. . . . The finding of the oldest glass and ironwork in Egypt is not a tribute to the superior civilization of the Egyptians at all, but rather to the superior preservative qualities of their dry sands. [Hugh Nibley, The World of the Jaredites, pp. 216-217]
Windows were also a part of Noah's ark: "A window shalt thou make to the ark" (Genesis 6:16).