Re: Water glass? Site glass?

Trycock,try cock, tri cock, gauge cock, or gage cock they are all the same. A series of valves on the backhead or on the water column (on large engines). Sometimes there were as few as 2 sometimes as many as 4 usually 3. They are used to show the level of the water in the boiler. In the early days locomotives didn't have a water glass but only try cocks. They are less accurate than water glasses because the water cam climb the backhead near the cock when it is open giving a false high reading. They are more reliable than a water glass because a plugged or restricted water glass tap can give a completely erroneous reading to the glass. that is why the water glass should be blown down frequently. The water level should return promptly and be "active". Under the new rules with 2 water glasses try cocks are not required.

By the way right up till the end the M&PP cog engines never had water glasses only gauge coks. How about that for exciting.

John Bush