From the back half of Melville’s Journal Up the Straits, as he makes it to Padua:
Wednesday April 1st. Rainy day. To the famous caffe of Pedrocci. Worth of its fame, being of great size and well furnished. Got a grave dark guide & started with great-coat &umbrella to see the sights – To the town hall. Wonderful roof (India) To the ….. palace to see the “Satan & his host.” Fine attitude of Satan. Intricate as heap of Vermicelli. Church of St. Antony & Shrine. Superb. Crutches & pictures. Bronze bas-reliefs. Goliath & David. &c. Promenade. – The Brenta flowing round it. Pleasant aspect of Brenta winding through town. To Giotto’s chapel. – The Virtues and Vice. Capital. The Scriptural pictures. – The Arena
The editor of my edition notes of “Satan and his host” that Melville is “pretty certainly referring to Giotto’s Last Judgment” and seems to assume he misidentified the Scrovegni chapel as an unknown palazzo, even though he later accurately identifies both it and its contents. And at first glance I could just possibly see describing Giotto’s Satan as “intricate as a heap of Vermicelli,” if only for the writhing limbs of the damned.
But I dug about some and found a better explanation in a work called Savage Eye: Melville and the Visual Arts, where the author identifies the unnamed palace as Palazzo Papafava and the work mentioned as Agostino Fasolato’s ~1750 La Caduta degli Angeli Ribelli (The Fall of the Rebel Angels). Not only does the title match better (who ever refers to the damned as part of Satan’s host?) and the identification salvage Melville from confused redundancy but the work itself far more resembles a heap of vermicelli.
The work – with a fuller description and history here – now resides in nearby Vicenza at the Gallerie di Palazzo Leoni Montanari.