“In deciding whether a transaction amounted to the transfer of a business regard must be had to its substance rather than its form, and the consideration must be given to the whole of the circumstances, weighing the factors which point in one direction against those which point in another. In the end the vital consideration is whether the effect of the transaction was to put the transferee in possession of a going concern the activities of which he could carry on without interruption. Many factors may be relevant to this decision though few will be conclusive in themselves. Thus, if the new employer carries on business in the same manner as before this will point to the existence of a transfer, but the converse is not necessarily true because a transfer may be complete even though the transferee does not chose to avail himself of all the rights which he acquires thereunder. Similarly, an express assignment of goodwill is strong evidence of a transfer of the business but the absence of such an assignment is not conclusive if the transferee has effectively deprived himself o the power to compete. The absence of an assignment of premises, stock-in-trade or outstanding contracts will likewise not be conclusive. If the particular circumstances of the transferee nevertheless enable him to carry on substantially the same business as before.”