Across time.

In the direction of the length.

synonyms: lengthways, lengthwise, longways, longwise.

Roget 200: lengthwise, at length, longitudinally, endlong^†, along; tandem; in a line etc. (continuously) 69; in perspective.    from end to end, from stem to stern, from head to foot, from the crown of the head to the sole of the from the crown of the head to the sole of the foot, from top to toe; fore and aft.    ... show more

With respect to longitude.