Simple shoji became fairly cheap (standardization has already been mentioned), so they were not restricted to the homes of the rich (see illustrations). Paper-and-wood construction is very liable to fire; densely-packed nagaya row houses were therefore also known as yakeya (, , burning houses). Fires were a major problem in Japanese cities well into the Meiji Period; homes (including their furniture and the standardized architectural modules, such as tatami and hiki-do and even floorboards) were made to be quickly packed up and carried away when fire threatened, leaving only the stripped pillars and roof, which could easily be pulled down by firefighters. Plate glass was introduced to Japan in the late 1800s. It was used in yukimi shoji (see above) and in paperless garasu-do (, Dutch loan-word garasu, glass). Some early garasu-do were divided into panes by mullions, like contemporary western windows (see images). The float glass technique, which made large panes of picture-quality glass cheap, was developed in the 1950s in the UK. The process was made profitable in 1960, and in the early sixties plants were licensed throughout the world, including in Japan. Japan had developed substantial domestic float glass production by 1965. As 1960s float glass produced large single-pane picture windows in Western architecture, some influenced by the architecture of Japan, it also had an effect on Japanese architecture. Float glass was widely applied to traditional kōshi frames, without much change to the traditional structure or appearance. In modern Japan, it is fairly common to have garasu-do (all-glass sliding doors) on the outside of the engawa (veranda under the eaves), and translucent shoji on the inside, especially in cold climates. A layer of paper shoji behind a layer of glass helps to insulate the house. Ama-do are still used to protect the glass; for instance, glass doors and shoji may get two grooves each, and ama-do a single additional groove just outside the glass. Shoji are common in the washitsu of modern Japanese homes; they may also be used instead of curtains in Western-style rooms. Aesthetics and culture The silhouettes cast through shoji, and visible on the darker side, are valued for their aesthetic effects. In his book on Japanese aesthetics and architecture, In Praise of Shadows, Jun'ichirō Tanizaki comments on the role of shoji in the interaction of light and shadows. Shoji also filter the outside light. How light is brought inside a traditional building, and