Jeff Sexton on
IN THE SUMMER of 1922 the late Dr. S. W. Stratton, then Director of the Bureau of Standards in Washington, knowing that I was contemplating a visit to Europe asked me to carry to his friend, Dr. Guillaume, the Bureau's standard meter for calibration with that of the international standard at Sevres near Paris. To be entrusted with so valuable an instrument which required personal handling all the way and such an introduction to so great a man in the horological world was a privilege indeed. The standard was, for some reason which I do not now recall, not ready when I sailed, but a letter of introduction carried me to Dr. Guillaume's good graces.
Years later at a luncheon given by Paul Ditisheim following a session of the French Academy of Sciences, Dr. Guillaume recalled with a not displeased memory that I had said to him at that first meeting. that as I had not had the honor of having known Hooke, Huyghens, Earnshaw or Breguet it was a consolation to meet the man now foremost in the world in his contributions to precision timekeeping. It was an hour to be prized. An audience of one, I sat before the master's blackboard as he sketched the history of his vast number of experiments leading to the final success in producing the nickel-steel alloy whose dimensions remained invariable under different temperatures, or Invar, a name proposed by Professor Marc Thury in an article in the JOURNAL SUISSE D'HORLOGERIE in 1897.
Charles-Edouard Guillaume was born the 15th of February, 1861, at Fleurier in the upper valley of the Swiss .T ura Mountains, a region which gave birth also to Berthoud and Breguet. For centuries the inhabitants of this locality had for the most part farmed in summer and worked at watchwork in winter. His grandfather Charles- Frederic- Alexandre Guillaume, after the French Revolution and out of sympathy with the ruling Prince, removed to London and established an important horolagical business which was successively presided aver by his three sons. The son Edouard returned to Fleurier and became the father of Charles-Edouard.
On the medal, struck off an the occasion of Dr. Guillaume's resignation as active Directer of the Bureau International des Poids et Mesures, shown in HOROLOGY of January this year, is an imprint of the house in which he was born and where he spent his youth and early schaaling, surrounded by men and women working at and discussing horological problems. At the age of fifteen years he was put in the upper classes af the Gymnasium, or Academy, at Neuchatel where, after two years, he was prepared to enter the Polytechnicum at Zurich, one of the foremast technical schools of Europe. In addition to the usual higher mathematics and sciences he devoted much time ta the languages and literature of bath Germany and France. His bent, however, was far physics. On finishing his schooling he became an officer of artillery and developed a passion far ballistics. It was then that he wrote "l'Initiatian a la Mecanique," a most clear and admirable work in mathematics. After graduation in 1883, at the recommendation of Dr. Adolphe Hirsch, Director of the Observatory of Neuchatel and Secretary of the Committee of the Bureau International des Paids et Mesures, the young engineer was given a position at the Pavilion de Breteuil at Sevres, France. The Bureau had been in existence for a few years. I t was engaged in making the meter standards and many accessories were necessary. It fell to Dr.Guillaume to study the mercury thermometer in the most profound manner. The Bureau was at this time searching for a metal better adapted and less costly for the standard lengths than that formerly used.
In 1891 a primary research was conducted by Dr. Guillaume to reconnoiter the qualities of nickel from the metrological point of view. About 1895 observations of the Director J. R. Benoit fixed attention upon certain alloys of iron and nickel. Here was for Dr. Guillaume his opportunity to carry out his experiments which have since become classic. The term experiments might mean making a great number of combinations of alloys and testing each product and thereby finding the one which was satisfactory, but research involved a much more difficult and profound system. Without going into the problem at all closely, for two very good reasons, the first of which being that I am not familiar enough with it to do so, and the second that it would require pages of mathematics, I can point out that there is involved in alloys the element of action quite different from the action of each component metal by itself. These actions closely observed are found to follow laws which can be expressed only in complicated mathematical formula. The determination of these laws and their mathematical expression involve not only vast numbers of trials but a genius for inventing modes of measurement and exact observation coupled with the mathematical ability necessary to reason out the next step.
During the previous century there was discovered the reason why a bimetal compensated chronometer or watch balance could be adjusted to only two places on the scale of temperatures. If it was correct at temperatures of say fifty degrees and eighty degrees it was found to gain two seconds or more per day at sixtyfive degrees. This was known as the middle temperature error and unknown numbers of inventive minds searched for a mechanical correction. We find the well known names of Molyneaux, Ullrich, Poole, Hardy, Dent, Kullberg, Bliss, Lund, Loseby, and many others. I have even in my small collection, more than twenty forms of auxiliary balances. Some of the forms gave good results under intelligent care but none were found sufficiently successful under existing conditions to warrant general use and were finally excluded by several governments far naval use. The difficulty in mechanically salving the problem was due to. the fact that while the balance spring grew weaker proportionately to, the increase of heat, which could be represented by a straight line if plotted an paper, the change in distance of the mass of the balance rim from the axis affected the rate not proportionately but as the square of the radius, which platted would approximate the arc of a circle. The two. platted wauld show a straight line cutting two. paints an the arc, at which paints the rate is the same. Between these two, paints there would show a gaining rate and beyond them a lasing rate.
It was Dr. Guillaume's skill, patience and persistence, which gave to. the horological world Invar for unchangeable dimensions of pendulums and balances, and Elinvar, which keeps constant strength under different temperatures far balance springs.
Many honors have came to. Dr. Guillaume among which was the Nobel Prize in 1920, corresponding member of the French Academy af Science, the Gold Medal of the Horological Society in London and the occasion in January when many scientific associations paid homage to. him and marked it with the striking of a medal aforementioned.