| A Calculus of Angels | |
|---|---|
| Author(s) | Gregory Keyes |
| Cover artist | Therese Nielsen |
| Country | United States |
| Language | English |
| Series | The Age of Unreason |
| Genre(s) | Fantasy |
| Publisher | Del Rey |
| Publication date | March 30, 1999 |
| Media type | Print (Paperback) |
| Pages | 406 pages |
| ISBN | ISBN 0-345-40607-9 |
| OCLC Number | 39695456 |
| Dewey Decimal | 813/.54 21 |
| LC Classification | PS3561.E79 C35 1999 |
| Preceded by | Newton's Cannon |
| Followed by | Empire of Unreason |
A Calculus of Angels is the second book in Gregory Keyes' The Age of Unreason series. It was initially published by Del Rey on March 30, 1999. A follow up to Newton's Cannon, the book is set in 1722 and continues the alternate history where Isaac Newton discovers that alchemy works, and a powerful science is built upon it.