The first stage of making hertasi burrows begins with creating “guest apartments” alongside the ramps. These are not just a courtesy for the humans; they are also where the hertasi stonecrafters get truly intimate with the rock around them. Probe spheres and spellwork imaging “soundings” are sent in from these locations, and once the native rock is mapped and found to be worthy, the apartments are given over to the humans, and the hertasi burrow tunnelling begins nearby. The burrow tunnels go level and deep in concentric circles around where the Heartstone will eventually be placed once the Vale is “roofed” at ground level.
A sturdy wooden bridge is built across the ravine, its center pole marking where the Heartstone will eventually be. Surveying lines radiate out from the pole, and at equidistant points tripods with pulleys are set up. From these the hertasi’s plumb bob drilling devices are slowly lowered. They “scoop up” earth and rock as they drop, increasing its plasticity and compressing it into the hardened sides of the shafts. Hertasi stand well back because the compression and tunnelling creates a lot of heat, which fires up out of the hole in a jet. When the plumb bob drill reaches a set depth, it is powered down and pulled back up. Then a homing crystal is lowered down into the hole after a day’s cooling period and left there. Eventually between thirty and sixty shafts are made on either side of the Vale, each shaft with a homing crystal at the bottom. These crystals are the targets that the sideways tunnelling will track on. The hertasi use a specialized set of magical digging and stoneworking tools that include a “cooler,” which comically looks like a spoon at the end of a polearm. The cooler sucks away the heat given off by the other tools; it is a vital tool as excavations increase in scale.
Hertasi diggers start in from the valley side and aim at the nearest homing crystal, then expand and reinforce the tunnel section once they’ve reached that crystal. Then the next crystal is aimed for, and so on, and eventually a circular ring tunnel is produced. This pilot tunnel is the reference ring and access for all the valleyside tunnel work that is to follow. It is from this main ring that the Vale’s water distribution, Heartstone cooling system, and the radiating underground magical tuning channels are built up.
Compressed, hardened stone is scooped out as a result of the tunneling process and is in turn either reformed into marbled brick or ground into concrete. One of the first durable structures built inside the guard walls at a new Vale site is a charcoal oven. One team splits, seasons, and stacks the local wood, while a second team makes a brick kiln. Brick and concrete work better than stonepulling in many applications, like pathways, and once the Tayledras scouts and the lesser Mages have secured the area, even the original palisade is ground down to make pathways. If the Vale site has good kaolin and clay in the area, ceramic bricks are the top choice; if there is a good source of lime nearby, concrete is preferred. If a coal seam can be mined, the fly ash is saved for a particular type of structural concrete. Cement and concrete have been used for thousands of years in Velgarth; Urtho’s Tower at Ka’venusho was a triumph of architecture and concrete use. Hertasi usually do the brickwork and pointing at a Vale site, but even among the Hawkbrothers there are human masons.
Depending upon the regolith of the Vale site, the upper rooms and corridors in the ravine’s sides could have either a glassy or a ceramic finish, caused by the compression effect of the devices firing the earth into a hardened crust. This could be used to great effect structurally, since the compression strength could be quite high once support ribs of a foot thick or more were formed. Convenient shelving is usually built between the support ribs.
The hertasi stonepulling devices of various shapes have the property of changing stone’s plasticity without creating a detrimental crystalline matrix. More accurately, stone pulling makes the stone draw like a pulled clay or molten glass into the desired shape, and then the crystalline structure that gave the stone strength does not form until the stone is “released” by the stonepuller. When stone is drawn out into its final shape, the large-area stonepuller, called the setter, aligns the crystallization inside the stone from all the previous, smaller pulls. This is why the soaring bridges and buttresses used to create rooms and floors underneath a Vale are effectively single-piece structures, since the setter fuses the subassemblies together into a contiguous form. The setter also smooths out walls, ceilings, and floors. Some of the small hills and mounds inside a Vale are actually hollow, with multiple rooms, created by stonepulling a dome and setting it, and then building a layer of soil over the dome for landscaping. Hertasi are experts at disguising structures.
The Tayledras’ famed bathing pools are stonepulled creations that make use of a network of heat-regulating formed-tunnel “pipes” that circulate water from the furnaces upward to the surface and to heat-sink cisterns down the Vale’s slope. Hot water is diverted to create artificial springs that bubble up to the highest level of the pools and then cascade over the sides to the progressively cooler pools. Bathing starts at the lowest, cooling levels, which is where the outright filth and dirt gets washed off; then the next higher levels are cleaner, warmer water, until the highest level is reached where the hottest water and most of the socializing can be found. The Pelagirs are brutal, and most of what sticks to a Pelagirs traveler also stinks and probably carries disease or toxins, so the hot pools are more than a hedonistic indulgence, they’re vital for health and hygiene.
It is important to remember, when you consider a Vale, that it is essentially a machine that houses a small city. The Tayledras Adepts in particular are technical and procedural in how they harness and refine the Pelagirs’ wild magic. This applies to their delicate spellwork as well. Subterranean workrooms are isolated from each other and put behind layers of physical shielding ranging from lead sheet to embedded crystal dust mats, so that subtle magic or “miniature” versions of Great Work spells can be laid out at low risk of interference. The floors are inscribed with diagrams and reference points, and their geometry act as an instruction set for what will happen during the course of a casting. Once the “model” is constructed, the spellwork is diagrammed, and hertasi scribes make records of every small detail, since when a Great Work is played out at full size, a “small detail” could affect an area the size of a city. These scribed accounts form a standardized reference for every Mage involved in the castings, much as architects have multiple sets of blueprints, and copies are eventually distributed to each Vale and Tayledras settlement.
Hertasi, being no strangers to magic use themselves and definitely no strangers to how Hawkbrothers do things, embed two or more of the main galleries of each Vale with the workrooms’ gridwork for spell construction, just in case some Pelagirs-wide catastrophe should need to be solved by a large-scale spell that, for some awful reason, could not be done above ground.
The arched galleries themselves are more than just (to the short hertasi) vast spaces to make bigger surface-dwellers feel more welcome; they are also meant for evacuations. Every Vale has enough room in the galleries to take in a complete Vale’s complement of gryphons, humans, and other species, plus their pets and Bondbirds, twice over, with sanitation and basic provisions for up to six days. Fresh air is brought in from the lowest levels inside the ravine, aided by waterwheels powered by the ravine’s stream, and circulates up to the surface by convection, belt-driven fans, and the bustle of activity under the Vale.