Upton ... promised his mother that working for Edison would help him "learn how to earn money." "Everyone must work and it is not always the most agreeable thing in the world," he confessed to her.

Edison hired Upton with the oblique promise that perhaps at some future date he might be assigned to take charge of a telephone system in another city. It was a struggle for the diligent, admittedly absentminded Francis, engaged to be married to his beloved Lizzie, and dreaming of a sedentary existence, to enter the world of commerce so quickly and on such an unexpectedly heady level, especially as he had hoped to return to Germany and "the quiet life." But within the year, this self-effacing and loyal soldier ... professing absolute faith in Edison's ability to achieve ultimate success, affectionately nicknamed "Culture" by his boss because of his introspective, learned mien, piano-playing talent, and impeccable educational credentials, had obtained a 5 per cent interest in all profits accrued from the electric light, a lucrative deal, considering the value of the stock offered by the Edison Electric Light Company eventually soared from $100 to $3,500 a share.

Edison liked and respected Upton, for the latter had acquired a brilliantly profound store of knowledge. And under Edison's guidance he soon gained the necessary experience to make theory and practice meet. It was always edifying to listen to their arguments, and often a group of us would gather round and drink in every word that was spoken. Reasoning and sparrings between Edison and Upton often led to new experiments ...

Francis Robbins Upton ... came to Edison at Menlo Park ... in November 1878. He was recommended by Grosvenor P Lowrey, a New Englander, who knew the Upton family that was connected with the philanthropist Peabody. Upton was a scholar and a gentlemen, brought up in a good New England fashion by a well-to-do family. He was educated both in this country and abroad, an possessed a mild, modest disposition combined with keen intelligence. His versatile knowledge of physics made him a most valuable assistant to Edison at that period.

While a bachelor, he was a star boarder at the Jordan house. In September, 1879, he took a vacation and went to Brunswick, Maine, to marry his college sweetheart, Miss Elizabeth F Perry. She was said to be the fairest damsel of the little college town. If I recall correctly, Charles L Clarke was present at the wedding ceremony, for he and Upton were once fellow students and chums.

I still remember when Upton brought his bride to Menlo Park. She was a fine, delicate young lady, well educated and of a kind, pleasant personality. Occasionally the Uptons had visitors from New England, among them Upton's sister Miss Sadie Upton. I recall her well. She was a smart, attractive young lady with a distinguished swing, and when she came once or twice to the laboratory, the boys all forgot their experimenting.

The Uptons occupied a fine old residence opposite the stairs leading down to the railroad station, and facing the old Post Road to Philadelphia. The homestead still stands; it has been kept ever since in such good order that it shows none of the ravages of time. In the summer of 1880, Upton took his young wife home to her parents in Brunswick, Maine. There their first child was born on August 24, 1880, and named for its mother, Elizabeth Fenno Upton.

While at Meno Park, Mrs Upton often attended Mrs Edison's informal parties, since she was a sociable and agreeable person whose pleasant demureness made friends everywhere. Mrs Edison frequently visited the Upton home; it seemed to me that these two were more friends than 'just neighbors'.

I was once with Mr Upton calculating some tables he had put me on, when Mr Edison appeared with a glass bulb having a pear-shaped appearance in his hand. It was the kind we were going to use for our lamp experiments; and Mr Edison asked Mr Upton to please calculate its cubical content in centimetres. Now Mr Upton was a very able mathematician, who after he finished his studies at Princeton went to Germany and got his final gloss under the great master Helmholtz. Whatever he did and worked on was executed in a purely mathematical manner and any Wrangler at Cambridge would have been delighted to see him juggle with integral and differential equations with a dexterity that was surprising. He drew the shape of the bulb exactly on paper, and got the equation of its lines with which he was going to calculate its contents, when Mr Edison again appeared and asked him what it was. He showed Mr Edison the work he had already done on the subject and told him he would very soon finish calculating it. "Why," said Edison, "I would simply take that bulb and fill it with mercury and weigh it; and from the weight of the mercury and its specific gravity, I'll get it in five minutes, and use a lot less mental energy than is necessary in such a fatiguing operation.