As I have already remarked, we were going from England to Gibraltar to observe the total eclipse of the sun. A large party of English astronomers were going to Algeria for the same purpose. The government had fitted up a naval transport for their use, and as I was arranging for a passage on a P. & O. ship we received a cordial invitation to become the guests of the English party. Among those on board were Professor Tyndall; Mr. Huggins, the spectroscopist; Sir Erastus Ommaney, a retired English admiral, and a Fellow of the Royal Society ; Father Perry, a well-known astronomer ; and Lieutenant Wharton, who afterward became hydrographer to the Admiralty.
The sprightliest man on board was Professor Tyndall. He made up for the absence of mountains by climbing to every part of the ship he could reach. One day he climbed the shrouds to the maintop, and stood surveying the scene as if he fancied himself on top of the Matterhorn. A sailor followed him, and drew a chalk-line around his feet. I assume the reader knows what this means ; if he does not, he can learn by straying into the sailors’ quarters the first time he is on board an ocean steamer. But the professor absolutely refused to take the hint.
We had a rather rough passage, from which Father Perry was the greatest sufferer. One day he heard a laugh from the only lady on board, who was in the adjoining stateroom. “ Who can laugh at such a time as this ! ” he exclaimed. He made a vow that he would never go on the ocean again, even if the sun and moon fought for a month. But the vows of a seasick passenger are forgotten sooner than any others I know of ; and it was only four years later that Father Perry made a voyage to Kerguelen Island, in the stormiest ocean on the globe, to observe a transit of Venus.
Off the coast of Spain, the leadingchains of the rudder got loose, during a gale in the middle of the night, and the steering apparatus had to be disconnected in order to tighten them. The ship veered round into the trough of the sea, and rolled so heavily that a table, twenty or thirty feet long, in the saloon, broke from its fastenings, and began to dance around the cabin with such a racket that some of the passengers feared for the safety of the ship. Just how much of a storm there was I cannot say, believing that it is never worth while for a passenger to leave his berth, if there is any danger of a ship foundering in a gale. But in Professor Tyndall’s opinion we had a narrow escape. On arriving at Gibraltar, he wrote a glowing account of the storm to the London Times, in which he described the feelings of a philosopher while standing on the stern of a rolling ship in an ocean storm, without quite knowing whether she was going to sink or swim. The letter was anonymous, which gave Admiral Ommaney an excellent opportunity to write as caustic a reply as he chose, under the signature of “ A Naval Officer.” He said that sailor was fortunate who could arrange with the clerk of the weather never to have a worse storm in crossing the Bay of Biscay than the one we had experienced.
We touched at Cadiz, and anchored for a few hours, but did not go ashore. The Brooklyn, an American man-ofwar, was in the harbor, but there was no opportunity to communicate with her, though I knew a friend of mine was on board.
Gibraltar is the greatest Babel in the world. I wrote home : “ The principal languages spoken at this hotel are English, Spanish, Moorish, French, Italian, German, and Danish. I do not know what languages they speak at the other hotels.” Moorish and Spanish are the local tongues, and of course English is the official one ; but the traders and commercial travelers speak nearly every language one ever heard.
I hired a Moor — who bore some title which indicated that he was a descendant of the Caliphs, and by which he had to be addressed — to do chores and act as general assistant. One of the first things I did, the morning after my arrival, was to choose a convenient point on one of the stone parapets for “ taking the sun,” in order to test the running of my chronometer. I had some suspicion as to the result, but was willing to be amused. A sentinel speedily informed me that no sights were allowed to be taken on the fortification. I told him I was taking sights on the sun, not on the fortification. But he was inexorable ; the rule was that no sights of any sort could be taken without a permit. I soon learned from Mr. Sprague, the American consul, who the proper officer was to issue the permit, which I was assured would be granted without the slightest difficulty.
The consul presented me to the military governor of the place, General Sir Fenwick Williams of Kars. He was a man whom it was very interesting to meet. His heroic defense of the town whose name was added to his own as a part of his title was still fresh in men’s minds. It had won him the order of the Bath in England, the Grand Cross of the Legion of Honor and a sword from Napoleon III., and the usual number of lesser distinctions. The military governor, the sole authority and viceroy of the Queen in the fortress, is treated with the deference due to an exalted personage; but this deference so strengthens the dignity of the position that the holder may be frank and hearty at his own pleasure, without danger of impairing it. Certainly, we found Sir Fenwick a most genial and charming gentleman. The Alabama claims were then in their acute stage, and he expressed the earnest hope that the two nations would not proceed to cutting each other’s throats over them.
There was no need of troubling the governor with such a detail as that of a permit to take sights ; but the consul ventured to relate my experience of the morning. He took the information in a way which showed that England, in making him a general, had lost a good diplomatist. Instead of treating the matter seriously, which would have implied that we did not fully understand the situation, he professed to be greatly amused, and said it reminded him of the case of an old lady in Punch who had to pass a surveyor in the street, behind a theodolite. " Please, sir, don’t shoot till I get past,” she begged.
Before leaving England, I had made very elaborate arrangements, both with the Astronomer Royal and with the telegraph companies, to determine the longitude of Gibraltar by telegraphic signals. The most difficult part of the operation was the transfer of the signals from the end of the land line into the cable, which had to be done by hand, because the cable companies were not willing to trust to an automatic action of any sort between the land line and the cable. It was therefore necessary to show the operator at the point of junction how signals were to be transmitted. This required a journey to Port Curno, at the very end of the Land’s end, several miles beyond the terminus of the railway. It was the most old-time place I ever saw; one might have imagined himself thrown back into the days of the Lancasters. The thatched inn had a hard stone floor, with a layer of loose sand scattered over it as a carpet in the bedroom. My linguistic qualities were put to a severe test in talking with the landlady. But the cable operators were pleasing and intelligent young gentlemen, and I had no difficulty in making them understand how the work was to be done. I have not seen or heard of them since, but should any one of them chance to see these lines, I wish him to know how pleasantly I remember my visit to his little station.
The manager of the cable was Sir James Anderson, who had formerly commanded a Cunard steamship from Boston, and was well known to the Harvard professors, with whom he was a favorite. I had met him, or at least seen him, at a meeting of the American Academy ten years before, where he was introduced by one of his Harvard friends. After commanding the ship that laid the first Atlantic cable, he was made manager of the cable line from England to Gibraltar. He gave me a letter to the head operator at Gibraltar, the celebrated de Sauty.
I say “ the celebrated,” but may it not be that this appellation can only suggest the vanity of all human greatness ? It just occurs to me that many of the present generation may not even have heard of the
Holding talk with nations,”
immortalized by Holmes in one of his humorously scientific poems. During the two short weeks that the first Atlantic cable transmitted its signals, his fame spread over the land, for the moment obscuring by its brilliancy that of Thomson, Field, and all others who had taken part in designing and laying the cable. On the breaking down of the cable he lapsed into his former obscurity. I asked him if he had ever seen Holmes’s production. He replied that he had received a copy of The Atlantic Monthly containing it from the poet himself, accompanied by a note saying that he might find in it something of interest. He had been overwhelmed with invitations to continue his journey from Newfoundland to the United States and lecture on the cable, but was sensible enough to decline them.
The rest of the story of the telegraphic longitude is short. The first news which de Sauty had to give me was that the cable was broken, — just where, he did not know, and would not be able soon to discover. After the break was located, an unknown period would be required to raise the cable, find the place, and repair the breach. The weather, on the day of the eclipse, was more than half cloudy, so that I did not succeed in making observations of such value as would justify my waiting indefinitely for the repair of the cable, and the projeet of determining the longitude had to be abandoned.
I had a mission which was vastly more important than any observation of the eclipse possibly could be. The question of the moon’s motion was then, as it is now, one of the unsettled ones in mathematical astronomy. The British government, in 1857, had published tables of the moon by Hansen, which were supposed to settle the question, at least for one or more centuries. But ten years had not elapsed after the publication before something was found to be wrong, and I suspected that, if the facts could only be brought out, the tables would be found to have been very largely in error for times before the beginning of accurate observations in 1750. The most promising place to search for older observations was the Paris observatory ; but the Franco-Prussian war made a visit thither impossible at the moment. So we determined to pass the winter at Berlin, waiting for the war to close.
We went by way of Italy. The Mediterranean is a charming sea in summer, but in winter is a good deal like the Atlantic. The cause of the blueness of its water is not completely settled; but its sharing this color with Lake Geneva, which is tinged with detritus from the shore, might lead one to ascribe it to substances held in solution. The color is noticeable even in the harbor of Malta, to which we had a pleasant though not very smooth passage of five days. Here was our first experience of an Italian town of a generation ago. I had no sooner started to take my first walk than a so-called guide, who spoke what he thought was English, got on my track, and insisted on showing me everything. If I started toward a shop, he ran in before me, invited me in, asked what I would like to buy, and told the shopman to show the gentleman something. I could not get rid of him till I returned to the hotel, and then he had the audacity to want a fee for his services. I do not think he got it. Everything of interest was easily seen, and we only stopped to take the first Italian steamer to Messina. We touched at Syracuse and Catania, but did not land.
Ætna, from the sea, is one of the grandest sights I ever saw. Its snowcovered cone seems to rise on all sides out of the sea or the plain, and to penetrate the blue sky. In this it gives an impression like that of the Weisshorn seen from Randa, but gains by its isolation.
At Messina, of course, our steamer was visited by a commissionnaire, who asked me in good English whether I wanted a hotel. I told him that I had already decided upon a hotel, and therefore did not need his services. But it turned out that he belonged to the very hotel I was going to, and was withal an American, a regular Yankee, in fact, and so obviously honest that I placed myself unreservedly in his hands. — something which I never did, with one of his profession, before or since. He said the first thing was to get our baggage through the custom - house, which he could do without any trouble, at the cost of a franc. He was as good as his word. The Italian custom - house was marked by primitive rigor, and baggage was subjected to a very thorough search. But my man was evidently well known and fully trusted. I was asked to raise the lid of one trunk, which I did; the official looked at it, with his hands in his pockets, gave a nod, and the affair was over. My Yankee friend collected one franc for that part of the business. He told us all about the place, changed our money so as to take advantage of the premium on gold, and altogether looked out for our interests in a way to do honor to his tribe. I thought there might be some curious story of the way in which a New Englander of such qualities could have got into such a place, but it will have to be left to imagination.
We reached the Bay of Naples in the morning twilight, after making an unsuccessful attempt to locate Scylla and Charybdis. If they ever existed, they must have disappeared. Vesuvius was now and then lighting up the clouds with its intermittent flame. But we had passed a most uncomfortable night, and the morning was wet and chilly. A view requires something more than the objective to make it appreciated, and the effect of a rough voyage and bad weather was such as to deprive of all its beauty what is considered one of the finest views in the world. Moreover, the experience made me so ill natured that I was determined that the custom-house officer at the landing should have no fee from me. The only article that could have been subject to duty was on top of everything in the trunk, except a single covering of some loose garment, so that only a touch was necessary to find it. When it came to the examination, the officer threw the top till contemptuously aside, and devoted himself to a thorough search of the bottom. The only unusual object he stumbled upon was a spyglass inclosed in a shield of morocco. Perhaps a gesture and a remark on my part roused his suspicions. He opened the glass, tried to take it to pieces, inspected it inside and out, and was so disgusted with his failure to find anything contraband in it that he returned everything to the trunk, and let us off.
It is commonly and quite justly supposed that the more familiar the traveler is with the language of the place he visits, the better he will get along. It is a common experience to find that even when you can pronounce the language, you cannot understand what is said. But there are exceptions to all rules, and circumstances now and then occur in which one thus afflicted has the advantage over the native. You can talk to him, while he cannot talk to you. There was an amusing case of this kind at Munich. The only train that would take us to Berlin before nightfall of the same day left at eight o’clock in the morning, by a certain route. There was at Munich what we call a union station. I stopped at the first ticket-office where I saw the word “ Berlin ” on the glass, asked for a ticket good in the train that was going to leave at eight o’clock the next morning for Berlin, and took what the seller gave me. He was a stupid-looking fellow, so when I got to my hotel I showed the ticket to a friend. “ That is not the ticket that you want at all,” said he ;
“ it will take you by a circuitous route in a train that does not leave until after nine, and you will not reach Berlin until long after dark.” I went directly back to the station and showed my ticket to the agent.
“I — asked — you — for — a — ticket — good — in — the — train — which — leaves — at — eight — o’ — clock. This — ticket — is — not — good — in — that — train. Sie — haben — mich — betrügen. I — want — you — to — take — the — ticket — back — and — return — me — the — money. What — you — say — can — I — not — understand.”
He expostulated, gesticulated, and fumed, but I kept up the bombardment until he had to surrender. He motioned to me to step round into the office, where he took the ticket and returned the money. I mention the matter because taking back a ticket is said to be quite unusual on a German railway.
At Berlin, the leading astronomers, then, as now, were Förster, director of the observatory, and Auwers, permanent secretary of the Academy of Sciences. I was especially interested in the latter, as we had started in life nearly at the same time, and had done much work on similar lines. It was several days before I made his acquaintance, as I did not know that the rule on the Continent is that the visitor must make the first call, or at least make it known by direct communication that he would be pleased to see the resident ; otherwise it is presumed that he does not wish to see callers. This is certainly the more logical system, but it is not so agreeable to the visiting stranger as ours is. The art of making the latter feel at home is not brought to such perfection on the Continent as in England ; perhaps the French understand it less than any other people. But none can be pleasanter than the Germans, when you once make their acquaintance ; and we shall always remember with pleasure the winter we passed in Berlin.
To-day, Auwers stands at the head of German astronomy. In him is seen the highest type of the scientific investigator of our time, one perhaps better developed in Germany than in any other country. The work of men of this type is marked by minute and careful research, untiring industry in the accumulation of facts, caution in propounding new theories or explanations, and, above all, the absence of effort to gain recognition by being the first to make a discovery. When men are ambitious to figure as Newtons of some great principle, there is a constant temptation to publish unverified speculations which are likely rather to impede than to promote the advance of knowledge. The result of Auwers’ conscientiousness is that, notwithstanding his eminence in his science, there are few astronomers of note whose works are less fitted for popular exposition than his. His specialty has been the treatment of all questions concerning the positions and motions of the stars. This work has required accurate observations of position, with elaborate and careful investigations of a kind that offer no feature to attract public attention, and only in exceptional cases lead to conclusions that would interest the general reader. He considers no work as ready for publication until it is completed in every detail, showing in this a conscientiousness which his fellow astronomers may sometimes have reason to regret, owing to the length of time they have to wait for his conclusions.
The old astronomical observations of which I was in quest might well have been made by other astronomers than those of Paris, so while awaiting the end of the war I tried to make a thorough search of the writings of the mediæval astronomers in the Royal Library. If one knew exactly what books he wanted, and had plenty of time at his disposal, he would find no difficulty in consulting them in any of the great Continental libraries. But, at the time of my visit, notwithstanding the cordiality with which all the officials, from Professor Lepsius down, were disposed to second my efforts, the process of getting any required book was very elaborate. Although one could obtain a book on the same day he ordered it, if he went in good time, it was advisable to leave the order the day before, if possible. When, as in the present case, one book only suggests another, this a third, and so on, in an endless chain, the carrying on of an extended research is very tedious.
One feature of the library strongly impressed me with the comparatively backward state of mathematical science in our own country. As is usual in the great European libraries, those books which are most consulted are placed in the general reading-room, where any one can have access to them, at any moment. It was surprising to see amongst these books a set of Crelle’s Journal of Mathematics, and to find it well worn by constant use. At that time, so far as I could learn, there were not more than two or three sets of the Journal in the United States ; and these were almost unused. Even the Library of Congress did not contain a set. There has been a great change since that time, — a change in which the Johns Hopkins University took the lead, by inviting Sylvester to this country, and starting a mathematical school of the highest grade. Other universities followed its example to such an extent that, to-day, an American student need not leave his own country to hear a master in any branch of mathematics.
I believe it was Dr. B. A. Gould who called the Pulkova observatory the astronomical capital of the world. This institution was founded in 1839 by the Emperor Nicholas, on the initiative of his greatest astronomer. It is situated some twelve miles south of St. Petersburg, not far from the railway between that city and Berlin, and gets its name from a peasant village in the neighborhood. From its foundation it has taken the lead in exact measurements relating to the motion of the earth and the positions of the principal stars. An important part of its equipment is an astronomical library, which is perhaps the most complete in existence. This, added to all its other attractions, induced me to pay a visit to Pulkova. Otto Struve, the director, had been kind enough to send me a message, expressing the hope that I would pay him a visit, and giving directions about telegraphing in advance, so as to insure the delivery of the dispatch. The time from Berlin to St. Petersburg is about forty-eight hours, the only through train leaving and arriving in the evening. On the morning of the day that the train was due I sent the dispatch. Early in the afternoon, as the train was stopping at a way station, I saw an official running hastily from one car to another, looking into each with some concern. When he came to my door, he asked if I had sent a telegram to Estafetta. I told him I had. He then informed me that Estafetta had not received it. But the train was already beginning to move, so there was no further chance to get information. The comical part of the matter was that “ Estafetta ” merely means a post or postman, and that the directions, as Struve had given them, were to have the dispatch sent by postman from the station to Pulkova.
It was late in the evening when the train reached Zarsko-Selo, the railway station for Pulkova, which is about five miles away. The station - master told me that no carriage from Pulkova was waiting for me, which tended to confirm the fear that the dispatch had not been received. After making known my plight, I took a seat in the station and awaited the course of events, in some doubt what to do. Only a few minutes had elapsed when a good-looking peasant, well wrapped in a fur overcoat, with a whip in his hand; looked in at the door, and pronounced very distinctly the words, “Observatorio Pulkova.” Ah! this is Struve’s driver at last, thought I, and I followed the man to the door. But when I looked at the conveyance, doubt once more supervened. It was scarcely more than a sledge, and was drawn by a single horse, evidently more familiar with hard work than good feeding. This did not seem exactly the vehicle that the great Russian observatory would send out to meet a visitor ; yet it was a far country, and I was not acquainted with its customs.
The way in which my doubt was dispelled shows that there is one subject besides love on which difference of language is no bar to the communication of ideas. This is the desire of the uncivilized man for a little coin of the realm. In South Africa, Zulu chiefs, who do not know one other word of English, can say “shilling” with unmistakable distinctness. My Russian driver did not know even this little English word, but he knew enough of the universal language. When we had made a good start on the snow-covered prairie, he stopped, looked round at me inquiringly, raised his hand, and stretched out two fingers so that I could see them against the starlit sky.
I nodded assent.
Then he drew his overcoat tightly around him with a gesture of shivering from the cold, beat his hands upon his breast as if to warm it, and looked at me inquiringly.
I nodded again.
The bargain was complete. He was to have two rubles for the drive, and a little something besides to comfort his shivering breast. So he could not be Struve’s man.
There is no welcome warmer than a Russian one, and none in any country warmer than that which the visiting astronomer receives at an observatory. Great is the contrast between the winter sky of a clear, moonless night and the interior of a dining-room, forty feet square, with a big blazing fire at one end and a table in the middle. The fact that the visitor had never before met one of his hosts detracted nothing from the warmth of his reception.
The organizer of the observatory, and its first director, was Wilhelm Struve, father of the one who received me, and equally great as man and astronomer. Like many other good Russians, he was the father of a large family. One of his sons was for ten years the Russian minister at Washington. The instruments which Struve designed sixty years ago still do the finest work of any in the world ; but one may suspect this to be due more to the astronomers who handle them than to the instruments themselves.
The air is remarkably clear ; the entrance to St. Petersburg, ten or twelve miles north, is distinctly visible; and Struve told me that during the Crimean war he could see, through the great telescope, the men on the decks of the British ships besieging Kronstadt, thirty miles away.
One drawback from which the astronomers suffer is the isolation of the place. The village at the foot of the little hill is inhabited only by peasants, and the astronomers and employees have nearly all to be housed in the observatory buildings. There is no society but their own nearer than the capital. At the time of my visit the scientific staff was almost entirely German or Swedish, by birth or language. In the state, two opposing parties are the Russian, which desires the ascendency of the native Muscovites, and the German, which appreciates the fact that the best and most valuable of the Tsar’s subjects are of German or other foreign descent. During the past twenty years the Russian party has gradually got the upper hand ; and the result of this ascendency at Pulkova will be looked for with much solicitude by astronomers everywhere.
Once a year the lonely life of the astronomers is enlivened by a grand feast, — that of the Russian New Year. One object of the great dining-room which I have mentioned, the largest room, I believe, in the whole establishment, was to make this feast possible. My visit took place early in March, so that I did not see the celebration ; but from what I have heard, the little colony does what it can to make up for a year of ennui. Every twenty-five years it celebrates a jubilee ; the second came off in 1889.
There is much to interest the visitor in a Russian peasant village, and that of Pulkova has features some of which I have never seen described. Above the door of each log hut is the name of the occupant, and below the name is a rude picture of a bucket, hook, or some other piece of apparatus used in extinguishing fire. Inside, the furniture is certainly meagre enough, yet one could not see why the occupants should be otherwise than comfortable. I know of no good reason why ignorance should imply unhappiness; altogether, there is some good room for believing that the less civilized races can enjoy themselves, in their own way, about as well as we can. What impressed me as the one serious hardship of the peasantry was their hours of labor. Just how many hours of the twenty-four these beings find for sleep was not clear to the visitor; they seemed to be at work all day, and at midnight many of them had to start on their way to St. Petersburg with a cartload for the market. A church ornamented with tinsel is a feature of every Russian village ; so also are the priests. The only two I saw were sitting on a fence, wearing garments that did not give evidence of having known water since they were made. One great drawback to the growth of manufactures in Russia is the number of feast days, on which the native operators must one and all abandon their work, regardless of consequences.
The astronomical observations made at Pulkova are not published annually, as are those made at most of the other national observatories, but a volume relating to one subject is issued whenever the work is done. When I was there, the volumes containing the earlier meridian observations were in press. Struve and his chief assistant, Dr. Wagner, used to pore nightly over the proof sheets, bestowing on every word and detail a minute attention which less patient astronomers would have found extremely irksome.
Dr. Wagner was a son-in-law of Hansen, the astronomer of the little ducal observatory at Gotha, as was also our Bayard Taylor. My first meeting with Hansen, which occurred after my return to Berlin, was not devoid of interest. Modest as was the public position that he held, he may now fairly be considered the greatest master of celestial mechanics since Laplace. In what order Leverrier, Delaunay, Adams, and Hill should follow him, it is not necessary to decide. To many readers, it will seem singular to place any name ahead of that of the master who pointed out the position of Neptune before a human eye had ever recognized it. But this achievement, great as it was, was more remarkable for its boldness and brilliancy than for its inherent difficulty. If the work had to be done over again to-day, there are a number of young men who would be as successful as Leverrier ; but there are none who would attempt to reinvent the methods of Hansen, or even to improve radically upon them. Their main feature is the devising of new and refined methods of computing the variations in the motions of a planet produced by the attraction of all the other planets. As Laplace left this subject, the general character of these variations could be determined without difficulty, but the computations could not be made with mathematical exactness. Hansen’s methods led to results so precise that, if they were fully carried out, it is doubtful whether any deviation between the predicted and the observed motions of a planet could be detected by the most refined observation.
At the time of my visit Mrs. Wagner was suffering from a severe illness, of which the crisis passed while I was at Pulkova, and left her, as was supposed, on the road to recovery. I was, of course, very desirous of meeting so famous a man as Hansen. He was expected to preside at a session of the German commission on the transit of Venus, which was to be held in Berlin about the time of my return thither from Pulkova. The opportunity was therefore open of bringing a message of good news from his daughter. Apart from this, the prospect of the meeting might have been embarrassing. The fact is that I was at odds with him on a scientific question, and he was a man who did not take a charitable view of those who differed from him in opinion.
He was the author of a theory, current thirty or forty years ago, that the farther side of the moon is composed of denser materials than the side turned toward us. As a result of this, the centre of gravity of the moon was supposed to be farther from us than the actual centre of her globe. It followed that, although neither atmosphere nor water existed on our side of the moon, the other side might have both. Here was a very tempting field, into which astronomical speculators stepped, to clothe the invisible hemisphere of the moon with a beautiful terrestrial landscape, and to people it as densely as they pleased with beings like ourselves. If these beings should ever attempt to explore the other half of their own globe, they would find themselves ascending to a height completely above the limits of their atmosphere. Hansen himself never countenanced such speculations as these, but confined his claims to the simple facts he supposed proven.
In 1868 I had published a little paper showing what I thought a fatal defect, a vicious circle in fact, in Hansen’s reasoning on this subject. Not long before my visit, Delaunay had made this paper the basis of a communication to the French Academy of Sciences, in which he not only indorsed my views, but sought to show the extreme improbability of Hansen’s theory on other grounds.
When I first reached Germany, on my way from Italy, I noticed copies of a blue pamphlet lying on the tables of the astronomers. Apparently, the paper had been plentifully distributed ; but it was not until I reached Berlin that I found it was Hansen’s defense against my strictures, — a defense in which mathematics were not unmixed with scathing sarcasm at the expense of both Delaunay and myself. The case brought to mind a warm discussion between Hansen and Encke, in the pages of a scientific journal, some fifteen years before. At the time it had seemed intensely comical to see two enraged combatants — for so I amused myself by fancying them — hurling algebraic formulæ, of frightful complexity, at each other’s heads. I did not then dream that I should live to be an object of the same sort of attack, and that from Hansen himself.
To be revised, pulled to pieces, or superseded, as science advances, is the common fate of most astronomical work, even the best. It does not follow that it has been done in vain ; if good, it forms a foundation on which others will build. But not every great investigator can look on with philosophic calm when he sees his work thus treated, and Hansen was among the last who could.
Under these circumstances, it was a serious question what sort of reception Hansen would accord to a reviser of his conclusions who should venture to approach him. I determined to assume an attitude that would show no consciousness of offense. Our meeting was not attended by any explosion; I gave him the pleasant message with which I was charged from his daughter, and, a few days later, sat by his side at a dinner of the German commission on the coming transit of Venus.
As Hansen was Germany’s greatest master in mathematical astronomy, so was the venerable Argelander in the observational side of the science. He was of the same age as the newly crowned Emperor, and the two were playmates at the time Germany was being overrun by the armies of Napoleon. He was held in love and respect by the entire generation of young astronomers, both Germans and foreigners, many of whom were proud to have had him as their preceptor. Among these was Dr. B. A. Gould, who frequently related a story of the astronomer’s wit. When with him as a student, Gould was beardless, but had a good head of hair. Returning some years later, he had become bald, but had made up for it by having a full, long beard. He entered Argelander’s study unannounced. At first the astronomer did not recognize him.
“ Do you not know me, Herr Professor ?'”
The astronomer looked more closely. “Mein Gott ! It is Gould mit his hair struck through.”
Argelander was more than any one else the founder of that branch of his science which treats of variable stars. His methods have been followed by his successors to the present time. It was his policy to make the best use he could of the instruments at his disposal, rather than to invent new ones that might prove of doubtful utility. The results of his work seem to justify this policy.