"Now the doctrine of laches in Courts of Equity is not an arbitrary or technical doctrine. Where it would be practically unjust to give a remedy either because the party has, by his conduct done that which might fairly be regarded as equivalent to a waiver of it, or where by his conduct and neglect he has though perhaps not waiving that remedy, yet put the other party in a situation in which it would not be reasonable to place him if the remedy were afterwards to be asserted, in either of these cases, lapse of time and delay are most material. . . . . . . Two circumstances always important in such cases are, the length of the delay and the nature of the acts done during the interval which might affect either party and cause a balance of justice or injustice in taking the one course or the other, so far as relates to the remedy."