Ad hoc arm rest

On the way back we had a double decker, the bottom was crowded so i took my seat atop. My usual bus has large window ledges which i use to rest my elbow on. One of the many shortcomings of the double decker is that it is not equipped with such ample shelf room. For about five minutes did not know that to do with my arm, so i put my book on the seat wedged it between myself and the side of the bus thus creating a rudimentary armrest, a little to low but it did. I will carry a larger book with me in future, I hope not to have to use it.