The triquetra has been found on runestones in Northern Europe and on early Germanic coins. It presumably had pagan religious meaning and it bears a resemblance to the Valknut, a symbol associated with Odin.
G Scale Trains are usually referred to as Garden Trains since they are the largest of the model trains and are used outdoors as well as indoors.
In O scale 1/4 inch equals 1 foot. Interestingly, O scale was originally called Zero Scale, because it was a step down in size from 1 scale. From the 1920s until after World War II, O scale dominated the model train market. But as model trains became more affordable for the average person, the space required to set up the tracks became a major consideration in purchasing model railroad trains.