All this happened before the beginning of his career as ambassador from the colonies to the king and government of England.

I cannot tell you of all of his discoveries in science.  He invented the lightning-rod, and, by trying many experiments, he learned more about electricity than the world had ever known before.

He made many curious experiments to discover the laws of heat, light, and sound.  By laying strips of colored cloth on snow, he learned which colors are the best conductors of heat.

He invented the harmonica, an ingenious musical instrument, in which the sounds were produced by musical glasses.

During his long stay abroad he did not neglect his scientific studies.  He visited many of the greatest scholars of the time, and was everywhere received with much honor.

The great scientific societies of Europe, the Royal Academies in Paris and in Madrid, had already elected him as one of their members.  The King of France wrote him a letter, thanking him for his useful discoveries in electricity, and for his invention of the lightning-rod.

All this would have made some men very proud.  But it was not so with Dr. Franklin.  In a letter which he wrote to a friend at the time when these honors were beginning to be showered upon him, he said: 

“The pride of man is very differently gratified; and had his Majesty sent me a marshal’s staff I think I should scarce have been so proud of it as I am of your esteem.”

* * * * *

XV.—­THE LAST YEARS.

In 1776 delegates from all the colonies met in Philadelphia.  They formed what is called the second Continental Congress of America.

It was now more than a year since the war had begun, and the colonists had made up their minds not to submit to the king of England and his council.

Many of them were strongly in favor of setting up a new government of their own.

A committee was appointed to draft a declaration of independence, and Benjamin Franklin was one of that committee.

On the 4th of July, Congress declared the colonies to be free and independent states.  Among the signers of the Declaration of Independence was Benjamin Franklin of Pennsylvania.

Soon after this Dr. Franklin was sent to Paris as minister from the United States.  Early in the following year, 1777, he induced the king of France to acknowledge the independence of this country.

He thus secured aid for the Americans at a time when they were in the greatest need of it.  Had it not been for his services at this time, the war of the Revolution might have ended very differently, indeed.

It was not until 1785 that he was again able to return to his home.

He was then nearly eighty years old.

He had served his country faithfully for fifty-three years.  He would have been glad if he might retire to private life.