At www.velikovsky.info/Isaac_Vail there is a brief mention of the man. I came across him many years ago when I took out a year's subscription to Donald Cyr's Stonehenge Viewpoint magazine under the false impression it would be all about the stone circle. Instead, the water canopy theory of Isaac Vail was the main focus of articles – and Stonehenge played a very minor role. Basically it involved the earth being girdled by a doughnut looking structure of ice crystals – the firmament of Genesis 1:6-8. However, in more recent years the idea of a periodical ring of ice crystals around the earth has been revived by Moe Mandelkehr, in SIS journals and in a book, The 2300BC Event, Outskirts Press of Denver:2006 (available through Amazon). According to www.velikovsky.info it was also a feature of Dwardu Cardona in 'The Reflective Canopy Modle and the Mytho-historical Record' in Aeon IV:4 (1996) and is also mentioned in Alfred de Grazia's Chaos and Creation (1981). Isaac Newton Vail wrote his ideas down in the 19th century but the full hypothesis was published in 1912 (and is still available as an Internet archive according to www.velikovsky.info). These rings of ice crystals, he thought, collapsed towards the earth and caused a succession of catastrophe – the last one of which he suggested coincided with Noah's Flood. Vail's rings, it seems, also contained various minerals such as gold, as well as limestone of all things. Vail also thought the ring system had a greenhouse effect, creating a universally warm earth (going along with geological discoveries at the time I suppose. He also said something unusual – there could not have been storms and tempests when there was a canopy as all such weather phenomena are caused by the Sun.
The full story of the canopy can be found at http://home.entouch.net/dmd/canopy.htm which I found via the search engine, keying in the man. In this interesting little article we are told the canopy theory was taken up by Young Earth Creationist writers, Whitcomb and Morris, in their book The Genesis Flood. Subsequently, the canopy theory has been revised by a number of authors as perceived wisdom claims such a ring of ice crystals would heat the earth to such an extent that life on the surface would become impossible. This suggests the thinking is that the canopy would act like the glass roof on a greenhouse and cook what was inside when it became too hot. Glass greenhouses, even in cloudy Britain, are usually shaded at the height of summer. The author describes himself as a former 'young earth creationist' and as their is no vitriolics in the article I assume he is now a 'long earth creationist' – but an interesting read whatever your inclination. It shows fairly conclusively that the Vail canopy was quite unlike the ice and dust temporary rings of Mandelkehr – formed by comet debris.