tribute to the poet with a challenge to the word insubstantial

"our revels now are ended. these our actors,
as i foretold you, were all spirits, and
are melted into air, into thin air:
and like the baseless fabric of this vision
the cloud-cappe'd tow'rs, the gorgeous palaces,
the solemn temples, the great globe itself,
yea, all which it inherit, shall dissolve,
and, like this insubstantial pageant faded,
leave not a rack behind. we are such stuff
as dreams are made on; and our little life
is rounded with a sleep"