“There are some arbitrations in which the arbitrator is expected to form his own opinion and act on his own knowledge without recourse to evidence given by witnesses on either side: such as an arbitrator who is to decide as to whether goods are up to sample, see Mediterranean & Eastern Export Ltd. v. Fortress Fabrics (Manchester) Ltd., (1948) 81 Lloyd’s Law Rep. 401; (1948) T.L.R. 337. But there are other arbitrations in which the arbitrator is expected to receive the evidence of witnesses and the submissions of advocates and to be guided by them in reaching his conclusion: such as arbitrations on shipping contracts or on building contracts. In such cases the arbitrator is often selected because of his knowledge of the trade so that he can follow the evidence in the absence of the other party, and so forth. In the present case if the defendants had been represented I have no doubt that the plaintiff’s experts would have been cross-examined so as to throw doubt on their findings and on their opinions: and the defendants would have called experts to support the line of cross-examination. The arbitrator would then have been able to form a judgment based on evidence other than his own. I cannot think it right that the defendants should be in a better position by failing to turn up. Nor is it right that the arbitrator should do for the defendants what they could and should have done for themselves. His function is not to supply evidence for the defendants but to adjudicate upon the evidence given before him. He can and should use his special knowledge so as to understand the evidence that is given, the letters that have passed, the usage of the trade the dealings of the market and to appreciate the worth of all that he sees upon a view. But he cannot use his special knowledge or at any rate he should not use it so as to provide evidence on behalf of the defendants which they have not chosen to provide for themselves. For then he would be discarding the role of an impartial arbitrator and assuming the role of advocate for the defaulting side. At any rate he should not use his own knowledge to derogate from the evidence of the plaintiffs’ experts without putting his own knowledge to them and giving them a chance of answering it and showing that his own view is wrong. Such is the way in which we dealt in the pensions cases when a medical expert was himself a member of the tribunal, see Moxon v. Minister of Pensions, [1945] K.B. 490 and Starr v. Minister of Pensions, [1946] K.B. 345 at pp. 353-354. I am afraid that the arbitrator fell into error here. He felt that it was his duty to protect the interests of the unrepresented party in much the same way as a Judge protects a litigant in person. But in a case like this I do not think it is the duty of the arbitrator to protect the interests of the unrepresented party. If the defendants do not choose to turn up to protect themselves, it is no part of the arbitrator’s duty to do it for them. In particular he must not throw his own evidence into the scale on behalf of the unrepresented party or use his own special knowledge for the benefit of the unrepresented party at any rate he must not do so without giving the plaintiffs’ experts a chance of dealing with it for they may be able to persuade him that his own view is erroneous.”