Show bridge made of knapsack A mexican engineer col lopez has planned and perfected a new kind of 0 bridge made of knapsacks the framework of each knapsack Is made of symmetrically arranged pieces of wood which can be spread on by means of hinges into boards of known dimensions the knapsacks are numbered and when the stream to bo be bridged Is reached the wooden forms can be promptly extracted from their canvas or leather coverings and quickly ly bolted into place A number of e eak perl peri ments have been made by the mill gitary authorities and it has been found that a knapsack bridge will ivill support as many men as can be crowded upon it in the military schools there are now working models of these bridges and the men and officers says the mexican herald have hate regular pi practice in the construction and operation of the puente the idea can also be applied to the scaling of walls or the climbing of barrancas barra barr ancas |