Brian is closing down his electrical wholesale business. Amongst the stock remaining in his warehouse are 400 television sets. He agrees to sell 300 of these televisions to Ian who pays for them in full by cheque and agrees to collect them the following week. Ian was busy the following week and didn’t get round to collect them until the end of the following month. Unfortunately, the day before Ian went to collect the televisions, Brian’s warehouse was broken into and 200 of the televisions were stolen. Brian cannot obtain any more stock but offers Ian delivery of the remaining 200 televisions.