In the poem [Spring and Fall,][1] Gerard Manley Hopkins uses diacritics where one would normally not see them. Does anyone know why?  Here is the poem:

> Márgarét, áre you gríeving    
Over Goldengrove unleaving?    
Leáves
> like the things of man, you    
With your fresh thoughts care for you,
> can you?    
Ah! ás the heart grows older    
It will come to such
> sights colder    
By and by, nor spare a sigh    
Though worlds of
> wanwood leafmeal lie;    
And yet you wíll weep and know why.    
Now no
> matter, child, the name:    
Sórrow’s spríngs áre the same.    
Nor
> mouth had, no nor mind, expressed   
What heart heard of, ghost
> guessed:    
It ís the blight man was born for,    
It is Margaret you
> mourn for.

Notice, for example, how he wrote "is" in the last line, compared to the one on the line before. Is it some kind of poetic license? Is it to indicate what syllables should be stressed?
  

[1]: https://www.poetryfoundation.org/poems-and-poets/poems/detail/44400?utm_medium=email&utm_campaign=Daily%20Poem%20of%20the%20Day&utm_content=Daily%20Poem%20of%20the%20Day%20CID_9e9107b3743c7dbd6a10286583cb392b&utm_source=Campaign%20Monitor&utm_term=Poem%20of%20the%20Day%20Spring%20and%20Fall