Technological advance the business of the lowest grade of slaves; desire for technological advance the result of making your body your master rather than your servant; and other topics: Early inventions were thought out by no other class of men than those who have them in charge to-day. We know that certain devices have come to light only within our own memory—such as the use of windows which admit the clear light through transparent tiles, and such as the vaulted baths, with pipes let into their walls for the purpose of diffusing the heat which maintains an even temperature in their lowest as well as in their highest spaces...