It will be seen from the foregoing that care isrequired in the appKcation of the card system,and that neglect must sooner or later lead to failure. There wasindeed a time when it seemed doubtful whether the card systemwould survive the first attempts. It was even tried and abandonedby some. These early failures were in the main due to the absenceof expert labour and to the higher order of accuracy required ascompared with the book system. The systems were not thenplanned out with that care that is bestowed upon them now. Onesystem would be started and presently there would be a decisionto alter it so as to fall in with riper experience. In the absenceof one system consistently adhered to the files soon got into achaotic condition until at last they had to be abandoned, for infact they had become useless.