With the utmost vigilance the tzar watched the administration of all the internal affairs of his empire, punishing fraud, wherever found, with unrelenting severity. The enterprise which now, above all others, engaged his attention, was to open direct communication, by means of canals, between St. Petersburg and the Caspian Sea. The most skillful European engineers were employed upon this vast undertaking, by which the waters of Lake Ladoga were to flow into the Volga, so that the shores of the Baltic and distant Persia might be united in maritime commerce. The sacred Scriptures were also, by command of the emperor, translated into the Russian language and widely disseminated throughout the empire. The Russian merchants were continually receiving insults, being plundered and often massacred by the barbaric tribes on the shores of the Caspian. Peter fitted out a grand expedition from Astrachan for their chastisement, and went himself to that distant city to superintend the important operations. A war of twelve months brought those tribes into subjection, and extended the Russian dominion over vast and indefinite regions there. Catharine, whom he seemed to love with all the fervor of youth, accompanied him on this expedition. Returning to St. Petersburg in 1724, Peter resolved to accomplish a design which he for some time had meditated, of placing the imperial crown upon the brow of his beloved wife. Their infant son had died. Their grandson, Peter, the son of Alexis, was still but a child, and the failing health of the tzar admonished him that he had not many years to live. Reposing great confidence in the goodness of Catharine and in the wisdom of those counselors whom, with his advice, she would select, he resolved to transmit the scepter, at his death, to her. In preparation for this event, Catharine was crowned Empress on the 18th of May, 1724, with all possible pomp. The city of Petersburg had now become one of the most important capitals of Europe. Peter was not only the founder of this city, but, in a great measure, the architect. An observatory for astronomical purposes was reared, on the model of that in Paris. A valuable library was in the rapid progress of collection, and there were several cabinets formed, filled with the choicest treasures of nature and art. There were now in Russia a sufficient number of men of genius and of high literary and scientific attainment to form an academy of the arts and sciences, the rules and institutes of which the emperor drew up with his own hand.