The Observatory – Claims to Fame

The second, and final, part of the article in the Jersey Catholic Herald:

The Observatory – Claims to Fame
By Father Pere Ray

Father Dechevrens did not wait until the observatory and tower had been completed before beginning his weather investigations, as the first published readings are dated January 1 , 1894.

A 'Stevenson' screen was erected nearby to house the thermometers, thermograph, hygrograph, evaporimeter, etc. The Stevenson Screen or thermometer screen is a standard shelter (from rain, snow and high winds, but also leaves and animals) for meteorological instruments, particularly wet and dry bulb thermometers used to record humidity and air temperature

Later inside the observatory building, the barometers, barographs, terrestrial magnetism instruments were placed, and in a special room, the fiat roof of which could be lifted, a transit instrument was put on a pillar, as, at that time, before wireless telegraph, the only means to keep the right time was to observe the passage of the sun or stars on the meridian. 

Soon the top gallery of the tower received the wind instruments, connected to the observatory itself by a multicore conductor, transmitting the electrical impulses to the recorders. A wind vane and anemometer were also installed on the top of the observatory.

Father Dechevrens made a very extensive study of the wind at two different levels. It is amazing to see how he has used all the data. making graphs calculating averages, percentages, for direction, speed, frequencies. Later a very complicated wind vane was put on top of the mast, crowning the tower, registering the direction and the horizontal and vertical current, of air, as well as their velocity.

This invention which he had realized in his workshop, Father Dechevrens had built by an instrument maker in Paris (not without arguments between the master mind and the craftsman!) and proved very efficient.

The director of the observatory was helped in his work, which at some moment involved readings day and night, by another Father his own age, and of course by young students of the Maison Saint Louis training for their future work in other observatories

From personal experience, between 1917 and 1921, I know that it was not always an easy job to climb the 250 steps of the tower to adjust an instrument on the small top platform, in all kind; of weather.

Being always on the alert to find new grounds of investigations, Fr. Dechevrens began a study of some electrical phenomena, known as telluric currents (from Latin tellūs, "earth") measured by galvanometers, between two electrodes pegged in the soil, showing the existence of an electrical tide, connected with the sea tides and the insulation. The Island had not then an electricity supply, and it was a choice place for such investigations.

Apart from regular detailed yearly bulletins, the work of Fr. Dechevrens and his colleagues is represented by some 130 memoires and contributions to scientific periodicals. The amount of copy books filled with column after column of figures in his small clear hand writing, preserved at the Observatory, is amazing. A few months before he died in 1923, he saw the publication, by the Office Meteorologique National de Paris, of his Etude du Vent a Jersey , 20 annees I' Observations: 1895 - 1914 a I'Observatoure Saint Louis. He died on December 6, 1923, awed 79.

Before we come to the work of his successors, a few words must be said about a machine invented by Father Dechevrens, the Campylograph, now exhibited in the mathematical section of the Palais de la Decouverte, in Paris.

By means of the horizontal movements of a pen on a revolving platen, complicated curves could be produced, according to mathematical formulae, on the principle of Lissajous designs. When Father Dechevrens had worked out on paper all the shapes arid sizes of the pieces, he sent the detailed specifications to an instrument maker, who insisted that the machine would never work. After assembly, however, it proved to be a very clever piece of machinery.

It was not to be a very successful commercial proposition, though we do know that another one was ordered by an Indian Prince. It could have been of use for the design of intricate regular patterns, as printed on currency notes. The inventor used it for science, as we can see from a memoire presented to the Société Astronomique de France, dated February 1907, entitled 'The Movement of the Planet Venus, in Relation to the Earth, Traced by the Campylograph Dechevrens, and Seen in Space with the aid of a Stereoscope.'

After the death of the founder of the Observatory, it seemed that his intensive work could not he continued on the same scale. At that moment the Zi-Ka-Wei Observatory needed more instruments and some were sent there from Jersey and as it was felt that to keep two important observatories was too onerous, China would have the preference. Therefore the local observations were reduced and would have ceased altogether when in 1924 someone interested in science always ready to help and undertake new tasks came again in Jersey.

He was Father Christian Burdo who with much enterprising courage and with the help of the mathematics and physics master at Maison Saint Louis kept the Observatory going. Ingenuity, skill and patience were rewarded and soon the recorders ticked away again and more students came to help and be trained.

Unfortunately the tower had suffered much from lack of paint and repair during the war years. In 1920 I undertook with some fellow students to hammer out rust and repaint the metal, beginning at the top as no workmen could be hound to undertake this somewhat perilous job. Later, when the working level was nearer to the ground plenty of labour was available and it seemed that the tower still had a long spell of life. It was not to be. The expenses of' keeping it in good condition of repair were too high and it was decided that it should be pulled down. There was at some moment a hope of reprieve. Only the top part, the most unsafe, would be taken down, leaving the structure two thirds of its original height. Messrs Hunt Bros, of 35 Commercial Street in a letter dated October 5 1928 stated that after due consideration they did not feel disposed to do the work. The Morning News on January 28 1929 wrote under the heading 'Going, going’:

'If you wake up one morning and can't see what we call the Jesuits' Tower (for want of a better name) don't imagine your eyesight has gone wrong. This old landmark has apparently outlived its usefulness, due no doubt to wireless(!)--for I hear that the owners are seeking suitable offers to have the tower taken down as far as the second tier. Demolishing such a structure from the top is not an easy business short of pitching it over in section, and doubt if the material saved would pay for the gear and labour needed to demolish it piecemeal.

The demolition was performed by A.O. Hill of the Dockyard, Dover. It proved to be a tricky operation as can be read in the Jersey Evening Post of February 20.

'The Jesuits' Tower has gone for at 11 this morning one of the finest landmarks the Island possessed swayed after a couple of seconds as the cables and tackle were tightened and then begun to fall, finally to crash in the exact place which had been marked out for its fall. So that in spite of several failures yesterday today has crowned the work of those responsible for the demolition with complete success.

Several other attempts were made yesterday evening but the tackle broke and eventually it was found necessary to produce new gear. This morning in addition to the new gear the two legs which had not been completely cut through had a little more cut away. At 11 o'clock the attempt was again made and this time as described met with success.

"So the Tower which was erected nearly 35 years ago is now nothing but a mass of twisted iron. The work of erecting it was carried out by a Belgian firm in 1894 . the work of demolition occupied just 24 hours but a great deal of breaking up requires to be done before the iron can be shipped to England. There is believed to be 40 odd tons."

"We understand that before the final decision to demolish the Tower was taken Maison Saint Louis offered it to the States of Jersey 'if the States were willing to defray the actual cost of keeping it in repair an amount expected to be somewhere about £120 every four years. The offer was declined."

The Climatological reports published annually in the Bulletin of the Société Jersiaise show the name of Father Christian Burdo, Director of the Observatory up to 1933. In 1934 another name appears and remains the same until now.

The successor to Fattier Burdo started his training under Father Dechevrens between1917 and 1921.

He gained more experience in another Observatory, in Madagascar, during two different periods, 1921-1924 and 1929-1932. That year the difficult task of positioning a new transit instrument for the verification of the longitude of Trananarive, posed too much for his sight and he had to return to Europe.

Within it year he had arrived back in Jersey, and was put in charge of the Observatory where no astronomical work was done. In Madagascar one of the duties of the new Jersey Observatory Director had been to look after the seismographs.

He undertook this new line locally, and in June 1936 made the first recordings of an earthquake, at precisely 15 hours 11 minutes, 45 seconds, some 90 minutes after the final adjustment had been made to the instrument and the recording mechanism put into action. This first record was that of a seism near the Kamchatka Peninsula, 5,450 miles away!

The seismograph the same as the instruments of Tananarive, is a Mainka, weighing more than a ton, set deeply on the rock in the basement of the Observatory. The static mass weighs half a ton, and the recording is made by means of levers which amplify the local movement of the soil 150 times, on a sheet of smoked paper progressing at the rate of a yard per hour' under a fine tracing pen.

Lent by the Faculte des Sciences de Strasbourg the centre of the International Union of World Geophysics for a period of at least two years, the seismograph is still here. It is estimated that since June 1936, some 4,000 earthquakes from all over the world, have been recorded locally, 'read' and interpreted.

A monthly bulletin is prepared and sent to Strasbourg and Kew Observatory, for publication, and classification in International Summaries, of some 700 stations.

During the German Occupation, the Observatory was kept going. (the seismograph had to be idle for lack of recording paper), not without untimely and unwelcome visits of' the Gestapo, the Feldgendarmerie, and officers of the Konmiandantur 515. By special permission the wireless set was allowed to be kept with the specification that it could be used only for scientific purpose.

One result of this unique (in the minds of the occupants) wireless set in existence on the Island was that the Observatory was put officially in charge of' giving the correct time to a jeweller's firm in town, in order that it could be shown to the public on a dial specially displayed. Thus according to the Germans, the public had no excuse not to know the correct time, when caught outdoors after curfew!

So, the work which Father Dechevrens began in 1894, with observations high up in the air at the top of the tower, has been continued, more humbly now, even underground, with seismology, with much reduced staff, especially since the occupation, and the end of the Maison Saint Louis, indeed, reduced to only one now, the writer of this historical account.