Horace Gray

“ Whether a witness called to testify to any matter of opinion has such qualifications and knowledge as to make his testimony admissible is a preliminary question for the judge presiding at the trial, and his decision of it is conclusive, unless clearly shown to be erroneous in matter of law. ”

“ The rule of damages, adopted by the court below, of deducting from the contract price the reasonable cost of altering the construction and setting of the machinery so as to make it conform to the contract, is the only one that would do full and exact justice to both parties, and is in accordance with the decisions upon similar contracts. ”

“ In such a case, it would be most unreasonable to compel the defendant, in order to entitle him to avoid paying the whole contract price, or to recover damages for the plaintiff's breach of contract, to undergo the expense of taking out the machinery, and the prolonged interruption of his business during the time requisite to obtain new machinery elsewhere. ”