Merge 2 lines into 1
First mark entries which are to be merged.Then choose Joining | Join rows (F4) or simply drag one row to the target. Here I dragged weather down to climate.
with a result like this:
The only differences are that weather is crossed out and climate is marked as joined in the left margin.
What about the details of the time-lines?
Double-click on the column which lists the different search-words, to get to see the details.
Here the Overall hits now show the total hits of all entries joined to climate.
Word count and other statistics cannot be merged. The reason is that in a given time-period (say period 17, August 2012) the 49 hits for climate and the 3 hits for weather in that month might or might not have been in the same set of text files dated August 2012.