This Wolf No.702 flame safety lamp use only for gas testing and was originally based on design by Friedrich Pieler in 1883. Before making a test, the flame was adjusted in pure air so that the point of the flame was exactly even with the top of the hood which surrounds the burner. It ran on alcohol rather than lamp oil. It was sensitive enough that any more than minimal gas showed strongly (above 1.25%) and any reading below that minimum was deemed as potentially dangerous.
Analytical cookies are used to understand how visitors interact with the website. These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc.
The _ga cookie, installed by Google Analytics, calculates visitor, session and campaign data and also keeps track of site usage for the site's analytics report. The cookie stores information anonymously and assigns a randomly generated number to recognize unique visitors.
Set by Google to distinguish users.
Installed by Google Analytics, _gid cookie stores information on how visitors use a website, while also creating an analytics report of the website's performance. Some of the data that are collected include the number of visitors, their source, and the pages they visit anonymously.
AddThis sets this cookie to track page visits, sources of traffic and share counts.
YouTube sets this cookie via embedded youtube-videos and registers anonymous statistical data.
1 year 1 month
Set by addthis.com to determine the usage of addthis.com service.