In 1897, if you mean Claude Monet. "When did HE paint ...? is an impossible question.
How can I know who you mean????
Water Lilies
Is it not obvious? He had this big pond made and saw to it that the water-lilies grew there in abundance just so he could paint this, his favorite subject.
monet
Claude Monet
He made hundreds of water lilies paintings, in all colors and shades.
Again and again during the last 30 years of his life.
He made hundreds of water lilies paintings between the 1890s and 1926.
Because they were his favorite subject between the 1890s and 1926.
Yes, you can mix paint with water to create a watercolor effect. By diluting the paint with water, you can achieve a transparent and fluid consistency similar to watercolor paint.
Because he loved his water lily pond, which always looked different from the day before.
Oil paint on canvas.
Can't find an exact figure. Anyway more than 60.