Strictly speaking, the NODES are those points of the sky against which the moon's center is projected at the moment when in its orbital motion it cuts through the plane of the earth's orbit.
"A Text-Book of Astronomy"
George C. Comstock
But, since there are two NODES past which the earth moves at least once in each year, there must be at least two solar eclipses every year.
"A Text-Book of Astronomy"
George C. Comstock
He then undertook a task which required nineteen years to perform, viz: to observe the moon throughout an entire revolution of her NODES.
"A Biographical Dictionary of Freethinkers of All Ages and Nations"
Joseph Mazzini Wheeler