Summary form only given. Cold atmospheric plasma jets have shown considerable promise for many industrial and medical applications. However, their fundamental studies are much behind. In this contribution, we present a preliminary study of a cold atmospheric plasma jet struck inside a ceramic tube and ejected into its surrounding ambient air. Both helium and argon are used as the working gas. The properties of the plasma jet considered include (1) the length and velocity of the plasma jet; (2) voltage, current and power; (3) nanosecond images; and (4) optical emission spectrum. Effects considered include (1) the flow rate of the working gas; (2) the applied voltage; (3) the excitation frequency; (4) the working gas. While many questions remain, this study offers an initial insight into the factors that may contribute significantly to the plasma jet properties.