New type of mobile crane is demonstrated in Letchworth, Hertfordshire.
M/S of one ton weight being picked up by new mobile type crane. Man puts ladder under crane. C/U of egg in hand. The egg is placed in jar under ladder. Weight is dropped slowly and supported on egg. M/S of crane driver. C/U cracked egg. The crane and operator then place the weight on top of pane of glass supported between planks of wood. The glass is bent but not broken.