"In order to decide whether a person carries business on his own account it is necessary to consider many different aspects of that person's work activity. This is not a mechanical exercise of running through items on a check list to see whether they are present in, or absent from, a given situation. The object of the exercise is to paint a picture from the accumulation of detail. The overall effect can only be appreciated by standing back from the detailed picture which has been painted, by viewing it from a distance and by making an informed, considered, qualitative appreciation of the whole. ..."