A line in the poem I read had a decasyllable.    From LearnThat.org. 

The deviations from the normal type, or decasyllable line, were they more numerous than, after allowance for the license of pronunciation, as well as the probable corruption of the text, they appear to be, would not.    From Wordnik.com.  [Blackwood's Edinburgh Magazine, Volume 57, No. 357, June, 1845] Reference

Ten-footed or ten-armed. demolish v. To annihilate. decasyllable n.    From Wordnik.com.  [Recently Uploaded Slideshows] Reference

How DID you learn the secret of writing the decasyllable line, and whence that sweet wailing note of tenderness that accompanies your song?.    From Wordnik.com.  [Roundabout Papers] Reference

Marlowe the tragic decasyllable, put into the hands of the still greater group who succeeded them an instrument, the power of which it is impossible to exaggerate.    From Wordnik.com.  [A History of Elizabethan Literature] Reference

Wyatt's awkwardness is not limited to the decasyllable, but some of his short poems in short lines recover rhythmical grace very remarkably, and set a great example.    From Wordnik.com.  [A History of Elizabethan Literature] Reference

I do not know, and it would probably be difficult to say, what was the first appearance of the decasyllable, which in German, as in English, was to become on the whole the staple measure of non-lyrical poetry and the not infrequent medium of lyrical.    From Wordnik.com.  [The Flourishing of Romance and the Rise of Allegory (Periods of European Literature, vol. II)] Reference

The doggerel of the earlier years had almost entirely disappeared, and in its place appeared the perfect concerted music of the stanzas (from the sonnet and the Spenserian downwards), the infinite variety of the decasyllable, and the exquisite lyric snatches of song in the dramatists, pamphleteers, and music-book writers.    From Wordnik.com.  [A History of Elizabethan Literature] Reference