This book has many virtues. It is not excessively long, and has many well-documented illustrations, although its somewhat small format forced me to deploy a magnifying glass to see the detail in many of the illustrations. It was written by a French professor and translated into English, but it reads quite easily.
Rather than discussing Newton exclusively, it describes much other work which formed a context for Newton's and it does this fairly precisely.

In particular, it claims that when Halley made his famous trip to visit Newton, he, Halley, had done some calculations to demonstrate that the more or less constant relationship of the period of a planet's orbit to its mean distance from the sun and the assumption that the force between it and the sun varied inversely with the square of the mean distance agreed. What Halley particularly wanted Newton's help with, was handling the extra detail that the orbits were not circular but elliptical. He, Halley, was stumped, but it turned out Newton, having developed calculus so fully had the answer.

Another interesting bit is about the determination of the circumference of the earth and verification that it bulges a bit in the middle. The distance along one arc of the meridian was measured very precisely at distinct locations. Under the Newtonian hypothesis, this distance should be shorter nearer the equator. This is something I'm having difficulty seeing clearly, but it is a nice precise point.

Some extracts from original sources, especially Voltaire's remarks on Newton's death and comparison with Descartes round out the book very nicely.

There are a few small errors; one image is described as showing a man looking through an early telescope, but it looks much more like a cross staff to me. The book also speculates a bit; for example, suggesting that Newton finished the 3rd book of his Principia out of fondness for Halley, who otherwise would have lost money on its publication. ( )