Shivering:Work is Never Done

Quick Walkthrough
# Find Tove the Unrestful in Bliss and speak with him twice about Calipers and Tongs.
# Find calipers. Find tongs. At least fifty each.
# Give them to Tove. After you give at least 100 total to him, speak with him again.

Detailed Walkthrough
Continuation
Tove the Unrestful can be found in Bliss, often at his home or The Choosy Beggar. When you first speak with him, he asks if you will continue to help him. His initial explanation for the strange greeting is that he keeps forgetting that people won't realize that he knows they will speak to him in the future, although he seems less than sure about even this. Regardless, Tove is quite secure despite his confusion and presses forward with his request. Tove explains that while he has perfected getting boats to float on the water, he has had less success in forcing the water to fly through air. Logically, a boat carried by flying water becomes a Skyboat. Tove requires at least 100 calipers or tongs to achieve the effect of keeping water airborne; he pays you five gold for each caliper or tong you bring him.

A Long Road
If you have 100 ready, you may simply select the Calipers and Tongs topic three more times to finish the mission for the minimum reward of 500 gold. You do not need to bring him tongs, as the quest will complete if you bring him 100 calipers. Alternatively, after agreeing to collect Calipers and Tongs you may go out into the wild and collect all the calipers and tongs you can carry. He will give you 5 gold per caliper or tong even over the minimum, and he has a limitless supply of funds to purchase them.

Calipers and tongs are most frequently found as clutter in random loot. Most crates and barrels have a chance of spawning either item; after three days, their contents will regenerate and you can check them again.

Places in the Shivering Isles with more than one guaranteed set of tongs and/or calipers include (none of these tongs will respawn; unless stated otherwise, the items can only be obtained by theft):

Bliss:
The Missing Pauldron contains 5 calipers and 2 tongs.
Common Treasures has 3 calipers downstairs, and 2 more upstairs.
Big Head's House Upstairs has 3 calipers.
Tove the Unrestful's House Upstairs has 2 calipers and 2 tongs.

Crucible:
Brithaur's House has 4 calipers and 1 tong upstairs.
Cutter's Weapons has 2 calipers.
Things Found has 3 calipers.
Sickly Bernice's Taphouse has 2 calipers.

Passwall:
Jayred Ice-Veins' House has 2 calipers,

Mania Region Ruins:
Ebrocca Crematorium has 1 calipers and 1 tongs (does not count as stealing).

Dementia Region Ruins:
Vitharn Keep has 1 calipers and 2 tongs (does not count as stealing).
Xaselm, Sanctum of Vivisection has 1 calipers and 1 tongs (does not count as stealing).

Cyrodiil:
In Cyrodiil, one notable location is Tidewater Cave, where there are three Kalperklan Trolls, each carrying 1-7 calipers (depending upon your character's level).  The trolls and their calipers will respawn after three days and therefore can be killed and looted repeatedly.

Who Needs Those?
After delivering all the calipers and tongs, discussing Calipers and Tongs once more results in Tove asking what he would need those for. Even before you've left conversation, Tove has begun working on a collapsible fork. Unfortunately, his wondrous Skyboat must be dismantled to provide the hinges he needs. While the Skyboat might not have existed, you can find a boat upstairs in his house; he hammers at it for hours with an iron war axe. Thankfully, there is no question that the gold is quite real.

Bugs
  This means that you can give him the regular calipers/tongs a second time, as long as you didn't give him more than 50 of each already.

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