The ornamental design for a portable gaslantern, as shown and described.
FIG. 1 is a front elevation view of a portable gas lantern showing a first
embodiment of our design having three support feet and a transparent
globe;
FIG. 2 is a top left perspective front view of a second embodiment of our
design having two support feet and a translucent globe, the second
embodiment being identical to the first embodiment except for the third
support foot and the globe; and,
FIG. 3 is a top left perspective view of the second embodiment shown in a
collapsed condition.
The broken line represents a gas cylinder for illustrative purposes and
forms no part of the claimed design.