For a reader already versed in the topics of this book, it presents a useful historical perspective. Giving an appreciation of what our predecessors fumbled through.The first topic has perhaps the strongest historical tie-in. Relating problems that bedevilled classical European and Asian mathematicians to the rise of calculus. These concered the sums of infinite series. Pondering this problem with no definitive solution was the status quo for centuries. It took the genius of Euler to finally furnish an answer. For the modern reader, this narrative shows one of Euler's masterpieces of deduction. Another topic is about numerical solutions of linear and non-linear equations. Today this is germane because of our computers. Yet, hard as it is to imagine, the methods were also pondered centuries ago, when all this had to be done by hand.