Make the fourth and
Last Platform
of pasteboard six inches square. When finished let the box measure three and one-half inches square and one and one-quarter inch high. Two more openings must be cut from your arched strip to shorten it sufficiently to fit in the last box platform, for this platform must also be cut into open arches. Build up the four platforms one on top of the other, as in [Fig. 369].
Place the centre of each platform exactly over the centre of the one beneath it.
To Find the Centre
take each platform in turn and lay a ruler very lightly on its top that no pressure may bend the arched sides; draw a pencil line across from the upper right-hand corner to the lower left-hand corner P, Q ([Fig. 370]); cross this line with another drawn diagonally across the square from the other two corners R, S ([Fig. 371]). The exact centre of the square top of the platform is at the dot T ([Fig. 371]), where the two lines meet and cross each other. Find the centre of each platform and very carefully puncture a hole through the centre with a coarse darning needle. You will have use for these centre marks when fastening the platforms together.
The Four Different Floors
of the original Gardens were supported by pillars and arches, as you have made yours, only the real platforms had more pillars under them. Between the pillars which formed the square of the first lower platform twelve arched passageways ran, entering from each of the four sides and dividing the ground beneath, equally between pillars and passages. There were rows and rows of pillars and arches that gave the effect of a honeycomb with open-sided cells. The arches proper were formed at the top of the many pillars which supported them, and all were built of the
Queer Square Bricks