“For the solution of this problem of the Punto Fijo,” the Cardinal continued, “seventy years ago Philip II of Spain offered a fortune, and later Philip III promised six thousand ducats of perpetual income and an annuity of another two thousand, while the Estates General of Holland offered thirty thousand florins…. By the way, Colbert, we’ve been keeping that Dr. Morin waiting for eight years….”
“Your Eminence, you yourself have expressed your conviction that this business of the lunar parallax is a chimera….”
“Yes, but to sustain his quite dubious hypothesis the man has effectively studied and criticized the others. Let us allow him to take part in this new project; he could enlighten Monsieur de San Patrizio. Offer him a pension; there is nothing like money to stimulate good inclinations. If his idea contains a seed of truth, we will be enabled better to ensure it for ourselves and at the same time we will avoid his feeling abandoned by his own country, and hence succumbing to the lures of the Dutch. It seems to me that it is indeed the Dutch who, seeing the hesitation of the Spaniards, have started negotiating with that Galilei, and we would be wise not to remain outside the matter….”
“Your Eminence,” Colbert said hesitantly, “you will be pleased to recall that Galilei died at the beginning of this year….”
“Really? Let us pray God he is happy, more so than he was in life.”
“And in any case his solution seemed for a long time definitive, but it is not….”
“You have felicitously anticipated us, Colbert. But let us assume that Morin’s solution, too, is worthless. Nevertheless, we will support it, cause it to rekindle the debate around his ideas, stimulate the curiosity of the Dutch, see that he allows himself to be tempted, and thus we will have set our adversaries on the wrong track for a while. It will be money well spent in any case. But we have talked enough of this. Continue, please; as San Patrizio learns I will learn with him.”
“Your Eminence taught me everything I know,” Colbert said, blushing, “but your kindness encourages me to speak.” With this, he must now have felt he was on friendly terrain: he raised his head, which he had kept bowed, and moved nonchalantly to the globe. “Gentlemen, on the ocean—where even if you encounter land, you do not know what it is, and if you go towards a known land, you must proceed for days and days amid an expanse of water—the navigator has no points of reference save the stars. With instruments that made the ancient astronomers illustrious, the altitude of a star above the horizon is established, its distance from the zenith is deduced; and knowing its declination, and since zenith distance plus or minus declination determines latitude, you know immediately on which parallel you are, that is, how much you are north or south of a known point. That is clear, I think.”
“A child could understand it,” Mazarin said.
“We must believe,” Colbert went on, “that in similar fashion it can be established also how far to the east or to the west of the same point you are, in short, at what longitude, or on what meridian. As Sacrobosco says, the meridian is a circle that passes through the poles of our world and through the zenith directly above our head. And it is called meridian because wherever a man is and at whatever time of the year, when the sun reaches his meridian, for that man in that place it is noon. Alas, through a mystery of nature, every means conceived to establish longitude has always proved faulty. How much does it matter, the profane might ask? It matters a great deal.”
Gaining confidence, he turned the globe, pointing to the outline of Europe. “Fifteen degrees of meridian, approximately, separate Paris from Prague, a little more than twenty separate Paris from the Canaries. What would you say to the commander of a land army who thought he was fighting at the White Mountain, and instead of killing Protestants he slaughtered the doctors of the Sorbonne at Mont-Sainte-Genevieve?”
Mazarin smiled, holding out his hands, as if to convey the expectation that such things would happen only on the correct meridian.
“The tragedy,” Colbert continued, “is that errors of such dimensions are made with the means used to determine longitude. And thus dreadful things happen: almost a century ago, that Spaniard Mendaña discovered the Islands of Solomon, lands blessed by Heaven with fruits of the soil and gold beneath the soil. This Mendaña fixed the position of the land he had discovered, came home to announce the event, and in less than twenty years ships had been fitted out for him four times to return to the islands and definitively assert the rights of Their Most Catholic Majesties, as they are called in their country, and what happened? Mendaña was never able to find those islands again.
The Dutch did not remain idle: at the beginning of this century they set up their Dutch East India Company, they created in Asia the city of Batavia as point of departure for many expeditions to the east, and they reached a New Holland; while other lands probably to the east of the Solomon Islands were discovered by English pirates, to whom the court of Saint James’s quickly granted charters of nobility. But of the Solomon Islands no one was to find a trace, and it is understandable that some are now inclined to consider them a legend.
Legendary or not as they may be, Mendaña actually found them, but, while he fixed their latitude properly, he mistook their longitude. And even if, through celestial help, he had established it correctly, other navigators seeking that longitude (and he himself, on his second voyage) did not know clearly what their own longitude was. And even if we knew where Paris was but could not establish whether we were in Spain or among the Persians, you see well, sir, that we would be proceeding like blind men leading the blind.”
“Truly,” Roberto ventured, “I can scarcely believe, with all I have heard about the advancement of learning in this century of ours, that we still know so little.”
“I will not give you a list of the methods proposed, sir, from the one based on lunar eclipses to the one considering the variations of the magnetic needle, on which our Le Tellier labored even recently, not to mention the loch method, which our Champlain guaranteed with many promises…. But all proved insufficient, and they will continue to be so until France has an observatory where all these many hypotheses can be tested. There is of course one sure method: keep on board a clock that always tells the time of the Paris meridian, then determine the local time at sea, and from the difference in times deduce the difference of longitude.
This is the globe on which we live, and you can see how the wisdom of the ancients divided it into three hundred sixty degrees of longitude, usually starting from the meridian that crosses the Isla de Hierro in the Canaries. In its celestial course, the sun (and whether it is the sun that moves or, as they have it nowadays, the earth, is a question of little consequence in this instance) covers fifteen degrees of longitude in one hour, so when in Paris it is midnight, as it is at this moment, then at one hundred eighty degrees of meridian from Paris it is noon.
So if you know for sure that in Paris the clocks say, for example, noon, and you can determine that in the place where you are now it is six in the morning, you calculate the difference in time, translate every hour into fifteen degrees, and you will learn that you are ninety degrees from Paris, and hence more or less here….” He turned the globe and indicated a point on the American continent. “But while it is not hard to determine the time in the place where you are making your calculation, it is quite difficult to keep a clock that will continue to tell the correct time after months of navigation on board a ship tossed by the winds, such movement causing error even in the most ingenious of modern instruments, not to mention hourglasses and water clocks, which to function properly must rest on an immobile plane.”
The Cardinal interrupted him: “We do not believe that Signor di San Patrizio need know any more for the present, Colbert. You will see to it that he is given further enlightenment during the journey to Amsterdam. After which it will no longer be we who teach him, but he, we trust, who teaches us. In fact, my dear San Patrizio, the Cardinal, whose eye has seen and will see—for a long time, let us hope—farther than ours, provided in the past for a network of trusted informants, who would journey to other countries, frequent the ports, question captains setting out on a voyage or just returning from one, to learn what the other governments were doing and what they knew that we did not, for—and this seems to me obvious—the State that discovers the secret of longitude, and manages to prevent word of it from spreading, will obtain a great advantage over the others. Now…” And here Mazarin paused again, once more smoothing his moustache, then folded his hands as if to concentrate and at the same time implore the support of Heaven. “Now we have learned that
