When Murray Rothbard laid eyes on this classic monograph, he cheered. Here we have a graphical presentation that explains the Austrian view of macroeconomics in contrast to the simple and even simple-minded approach of the Keynesian aggregates.
The value here is to highlight the distinct emphasis of the Austrian School: time matters, capital is heterogeneous, interest is not arbitrary, investment reflects human volition, production plans adapt to prevailing prices, and many more points that are completely lost on the flattened-out world generated by Keynesian mythology.
Roger Garrison has expanded on these expositions over the years but this monograph is the core presentation that has influenced so many.