E. L. Pearce 
Model Boiler-Making – A Practical Handbook on the Designing, Making, And Testing of Small Steam Boilers [EPUB ebook] 

First published in 1920, this is a new digital version of the fifth edition.
E.L. Pearce was prompted by the editor of ‘The Model Engineer’ to write a book on boiler making for the amateur model maker. The book contains rules and explanations for calculating the proportions and methods of constructing model boilers.
The author gives examples of the different varieties of boilers used, along with the alternative methods of building, showing how flanging may be dispensed with to a certain extent, and indicating where it is necessary to depart from the usual design of full-sized boilers.