Avoiding leaks is essential for accurate measurement of biogas production by batch assays. Here we present a simple method for detecting leaks and correcting results, based on the change in bottle mass during incubation. Three experiments were carried out using pure chemicals, wastewater sludge, and other complex substrates to test and demonstrate the method, and leaks were detected in all three. The frequency and magnitude of leakage was related to headspace pressure and the number of times bottle septa had been punctured. Comparison to an independent estimate of leakage in two experiments showed that the proposed method is accurate. This mass-based approach can generally be used to detect leaks as small as 20% of total biogas or methane production, or lower when biogas production is high relative to the precision of mass measurements. Additional research is needed to improve the sensitivity of the method and to better understand the causes of leakage. Given the potential importance of leaks and the simplicity of leakage measurements, we recommend that this method is always used in batch biogas assays.

That many divines during the middle decades of the seventeenth century were filled with high hopes for the Church's future, and that many of these high hopes were expressed in millenarian terms is by now a commonplace. That, furthermore, this phenomenon did not appear out of the blue and must have had a prehistory would be evident to most. But how far back should one go to find its roots? More than twenty years ago William Lamont argued in his controversial study Godly rule that Elizabethan reformers shared with their more radical brethren of the revolutionary years the hope of ‘godly rule’, a term he never clearly defined but which he nevertheless called millenarian. He singled out John Foxe as the chief spokesman of the ‘godly rule’ idea, and moreover claimed that Foxe was the one who above all ‘made the pursuit of the millennium respectable and orthodox’ in England. The idea that Foxe was a millenarian, even the chief spokesman of millenarianism in Elizabethan England, has not found general approval. In well-documented studies on Foxe, the British apocalyptic tradition, or the English Reformation, scholars such as Bernard Capp, Viggo Norskov Olsen, Richard Bauckham, Katharine R. Firth and Patrick Collinson have all denied that Foxe believed in a this-worldly and future period of peace and ecclesiastical felicity; they have instead drawn attention to his view of end-time persecution, and to his belief in the imminent end of the world.