The Infernal Device (Professor Moriarty #1) (1979)

Michael Kurland has written a series of novels in which Moriarty is the hero: His organisation of crime is the method by which he raises the money required for his experimental physics apparatus. In the first book of the series, The Infernal Device, he foils a plot against Queen Victoria, reluctantly allying with Sherlock Holmes. From the twisting alleyways of Constantinople to the teeming streets of London's East End... A spectre is haunting Europe. A man who is both fiend and genius. His name is Trepoff. His creed is anarchy. Abduction, assassination, atrocity mark his path across Europe. The Russians hire Moriarty to track him down. Sherlock Holmes, in turn, is in pursuit of Moriarty. But fate has one more card to play. The great detective and the Napoleon of crime are thrust into an unholy alliance as Trepoff moves into his final and most devastating gambit....