From time to time she jogged Lord Salisbury's elbow, asking whether he had yet been able to obtain trustworthy figures, and beseeching him to initiate a great irrigation policy. "Do not for a moment imagine," he wrote (Feb. 27, 1876), "that I have forgotten the question. The more I go into it, the deeper the mystery appears. Every one who has a right to entertain an opinion on it vindicates that right by entertaining a different one from his neighbour. General Strachey and Sir Barrow Ellis have been engaged upon the matter for years. Both of these assert with confidence that one set of statements is true, while the Government of India, backed by Mr. Thornton, our excellent Public Works Secretary, assert it with no less confidence to be false.... When I am able to get a little light I will let you know; but as long as my oracles flatly contradict each other, I am not likely to get nearer certainty than I am now." As Lord Salisbury was disinclined to a Committee of experts, she begged him to procure returns from India, and she drew up a model form of inquiry, on which particulars might be asked of the extent of cultivated land in each district, the amount of land under irrigation, the cost of annual repairs, and so forth, and so forth. Lord Salisbury took the suggestion into consideration, and some returns were called for, but nothing came of it for the time. Miss Nightingale then tried to obtain information in another way. There were, she was told, masses of data in the India Office itself, which only needed analysis and tabulation to yield valuable results. Lord Lawrence had introduced to her Mr. Edward Prinsep (late Settlement Commissioner, Punjab) as a man likely to be helpful in such work. She made friends with him; Sir Louis Mallet gave facilities, and Mr. Prinsep began making researches on Miss Nightingale's behalf. Unfortunately for her success, she had the correctitude to ask Lord Salisbury's permission. Lord Salisbury referred her request to the Revenue Department, who in a solemn minute represented the serious precedent that would be set by allowing an outsider to delve in official archives, and Mr. Prinsep had to discontinue his researches. "You are doubtless aware," Sir Louis Mallet told her dryly, "that in the India Office opinions diametrically opposed are usually entertained on every subject which is discussed." There was only one certainty, he added, that any decision taken at one time would be reversed at another. Ultimately a good deal of information was collected by a Select Committee of the House of Commons on Public Works in India (1878) and by Famine Commissions. Returns, such as Miss Nightingale asked for, are now regularly made.