The little table embedded in this text tells a more telling tale. One of the swift change from top- to bottom-fermentation in 19th century Bohemia. It was the start of the Lager boom which still hasn't quite petered out.
1865 1870 1875 High Fermentation 281 81 18 Low Fermentation 135 459 831
Thus in ten years the number of high-fermentation breweries fell from 281 to 18, while the number of low-fermentation breweries rose from 135 to 831. The sole reason for this vast change—a change which involves a greater expenditure of time, labour, and money—is the additional command which it gives the brewer over the fortuitous ferments of disease. These ferments, which, it is to be remembered, are living organisms, have their activity suspended by temperatures below 10º C., and as long as they are reduced to torpor the beer remains untainted by either acidity or putrefaction. The beer of low fermentation is brewed in winter, and kept in cool cellars; the brewer being thus able to dispose of it at his leisure, instead of forcing its consumption to avoid the loss involved in its alteration if kept too long. "
"The Fortnightly, Volume 26" edited by John Morley, 1876, pages 561-562.
That's a pretty rapid change. In a single decade top-fermentation all but disappeared.