Galileo’s confinement in Florence was so rigorous that at Easter a special permission from the Inquisition was required to allow him to go to the little Church of San Giorgio, very near his house, to confess, to communicate, and to perform his Easter devotions,[540] and even this permission only extended expressly to the Thursday, Good Friday, Saturday, and Easter Sunday.[541] On the other hand, as appears from the dates of his letters,[542] he was allowed, during June, July, and August, to go several times to and fro between his villa at Arcetri and Florence. Galileo was now once more to discover how rigidly he was watched by the Inquisition. His negotiations with the States-General, in spite of the urgent intercession of such men as Diodati, Hortensius, Hugo Grotius, Realius, Constantine Huyghens (Secretary of the Prince of Orange, and father of the celebrated Christian Huyghens), and others, had not led to any result. His proposed method of taking longitudes at sea, well worked out as it was theoretically, presented many difficulties in practical application. His methods of precisely determining the smallest portions of time, and of overcoming the obstacles occasioned by the motion of the vessel, did not prove to be adequate.[543] He had endeavoured, in a long letter to Realius of 6th June, 1637,[544] to dismiss or refute all the objections that had been made; but this did not suffice, and although the States-General acknowledged his proposal in the main in the most handsome terms, even accepted it, and offered him a special distinction (of which presently), it appeared necessary to have some personal consultation on the subject with the inventor. For this purpose, Hortensius, who had also a great desire to make Galileo’s acquaintance, was to go to Florence.[545] The Inquisitor-General heard that a delegate was coming from Germany to confer with Galileo on the subject. He at once reported this on 26th June to Rome,[546] whence he received instructions under date of 13th July from the Congregation of the Holy Office, that Galileo _must not receive the delegate if he were of a heretical religion, or from a heretical country_, and the Inquisitor will please communicate this to Galileo; on the other hand, there was nothing to prevent the interview _if the person came from a Catholic country, and himself belonged to the Catholic religion_; only, in accordance with the previous regulations, the doctrine of the double motion of the earth must not be spoken of.[547]