Since I now have plenty of mercury, a mercury thermometer would be nice to start with, as thermometers have many uses. The problem is that glass mercury thermometers like many other measuring instruments and constructions require long narrow glass tubes, for things like seeing water level on a steam tank as long as the glass tube endure the pressure, but a mercury thermometer requires a very narrow preferably hair thin channel because the thermal expansion of the metal is small.

The glazier gets another visit and he is happy to see me until I explain what I want. But he has already made glass tubes, so narrower should just be to pull it out faster? Maybe I can use my gas burner to the tube heat up, melt together and blow a bubble and so on. So I ask the glazier to make lots of glass tubes, some U and S shaped but above try to make them all straight, and some with finger-sized interior and some as narrow as possible. I need tube lengths of 10 to 40cm, but longer is better as I can cut down, and I would like some up to a meter or more if he can make them, for barometers and the like, and he should also let some larger tubes seal at the end so I can use them as test tubes. Short tubes or in funny bends shouldn't be thrown but can be useful. He will probably have to make some tools and jigs, and we discuss problems and possible solutions.

Mercurys thermal expansion coefficient is small, and something that expands more would be easier, such as ethanol, but ethanol has a poorer temperature range which the thermometer will operate within. Anyway, the narrower the channel, the more movement for a certain volume, and the less mercury is needed. It is possible to compensate with a large amount of mercury in the bubble, and I can make a thermometer with a deciliter of mercury, but I hope I won't need it as it limits what the thermometer can be used for due to thermal mass, and weight affects durability. Getting the mercury into the bubble becomes difficult if it is permanently sealed, but it is possible with a vacuum and centrifugal force. The bubble doesn't have to be glass and permanently attached to the tube, it is only practical if it is. I can combine them with something like ceramics or something, or make the bubble in ceramics. The problem is that the joint must become tight and if the thermometer is exposed to far too much temperature difference, the ceramic and glass will not have the same expansion and it will either break or it will come loose depending on which one expands the most. So if possible, it is best to keep the thermometer completely in glass.

The glazier doesn't have a blowtorch or gas burner and I wonder if I can do something that can burn with a high temperature, but my only current option is my jetboil gas kitchen. It won't burn totally clean, but it will be hot. I need to test with the an oil lamp, but I don't think it can reach a sufficiently high temperature, because the color is wrong. Hydrogen would be best as i burns clean without sooting, but collecting hydrogen and burning it is not fun, even if hydrogen is somewhat easy to produce by electrolysis of water. I forsee a future with hydrogen explosions.

Maybe I should try gengas, also known as wood gas? Can it be stored in any usable pressure? How hot will that burn? It was big once upon a time, and during World War II petrol and diesel shortages, half of Swedens vehicles were converted to wood gas. It is still used in the Third World, in the wilderness and in North Korea. The principle is simple with 'burning' carbon-based biomass, often wood or coal, and cooling down and purifying the gas formed, to then feed into a petrol or diesel engine. Getting the tar away from wood is important, and to increase the efficiency of combustion etc. The right type of petrol engine doesn't really need to be modified but can run on petrol and switch to wood gas after start-up. A modern solution could probably get the right timing with the engines electronic control system, and use sensors and the like to regulate itself instead of learning to do it manually. The details will be a pain to get right for an efficient system, but it can be very practical here in combination with steam engines.

Maybe I should try to make acetylene? Koks and Calcium Oxide burned with a electric arc creates it, but it need to be compressed and stored. Easy to say, but not so easy to do. Factories used to make their own acetylene before they figured out how to store it in gas cylinder without blowing up. A porous mass and acetone was the key to that, but the good thing is that I need to keep the pressure low for it to work. 7 bar is the modern limit compared to 200 bar for a oxygen gas cylinder, but it can blow if subjected to shock and 1.4 bar is feed to the torch. I can probably forget about making oxygen. I really need to make safety equipment before I mess with acetylene and stuff. Guess I have had an unexpected use for getting an limited ADR license. Way to hard to do right now, but it is added to the list.

Again, my mind have gone away from the topic. Glass. I also need to think about annealing the glass when the work is done. But the glazier accepts the job and will make sure it is well packaged in wood chips and sawdust and will also ship with some of the better failures.

I take a detour to the man doing stone work, and I order a millstone and a bedstone from him. It will be a difficult job to get it right, and honestly I expect to have to grind the wheels a bit to make the surfaces good. But the stone worker can cut the hole and pattern I ask into two flat round stones. If it work well I can absolutely promise him a lot of work in the future. There will be many mills.

Next I visit bladesmith Olafr to see his progress, and if he has finished my stamps. They look good. The Triangle A and Triangle R logo was of course the hardest to make, but he has made those stamps in two sizes. He's finished his second sword, and his personal knife. Its a copy of the knives he made for me, but with a very beautiful ornate wooden grip, which he will continue to carry in his own belt as a reminder. The second sword is just as beautiful and a real work of art. Beautiful amber inlaid in a golden grip, and I give Olafr well-deserved praise.

He looks sad as we talk about his sword, and he admits that he has no new work he is excited about. He has spent extra time making these, just because he didn't want to return to his normal work. He has hardly done any work the last few days. The apprentices work. Sure, he has several orders for ordinary swords, spears and axes, but it is just boring repetitive work. No challenge.

I guess I my timing is perfect, and I casually say that I have a couple of special projects if he is interested, and I have steel lumps on my ship. Yeah, that lit a glow in Olafrs eyes. So we find a quieter spot and order people away. I inform him that he needs to keep it a secret but his apprentices can be told if he trusts them and need their help, to which he quickly and very seriously swears. First I show him my folding knife prototype in brass, and show how I can open it with one hand and how the lock works. Iselin loves pockets, and a folding knife with a pocket clip would be a good little wedding gift she probably like. There are apparently simpler folding knives, but it has never been popular, partly because people don't have pockets and a knife needs to be caried. A knife sheath is practical to carry the knife in so it might as well be a good normal cheaper knife. But Olafr loves the design and layout, and like the thumb movement to fold out the blade, or with a flick of the wrist. It is a fairly simple design, but when unfolded it feels safe and stable. I want a prototype, followed by a real pretty one marked with Iselins name on the grip, and before midwinter.

Then I show him the really secret stuff, and take up the flintlock prototype and drawings from the bag while I explain that this will be a hunting weapon based on sejd. Olafr hardly believes me, but I remind him of the duel I did and the thunder. I have been thinking and done some tests, and come up with a weapon others can use, that use sejd from me. It is a powerful weapon, but intended for hunting animals, not elves, and it requires special parts which will be hard to do. I have been inspired by the work he's already done for me, how beautiful my cane is, and the parts for it. Olafr just stares at me. On the drawings and parts. He carefully makes sure he has understood;

"These parts and drawings are for making weapons that use sejd for hunting?"

"Yes."

"A sejd weapon that anyone can use. Like a crossbow?"

"Yes."

"But just like the steel swords, these are not meant to be sold, and there won't be many."

"Right. They're for my own use and without sejd from me, they will just be beautiful wood and metal things that can make sparks; they are just bad clubs of wood and metal. Most likely, in the future I will give one away as I have promised my bodyguard Alith who likes hunting a special gift, and as you can understand she has some trouble in properly using a bow."

Olafr casts a quick eye at Alith and smiles, but then ignores her and takes a deep breath as he calmly lays his hands on the drawings.

"I will gladly make these to the best of my skill and with the same focus as the swords, if I can try it once for myself."

I feel a growing smile on my face: "Olafr, build it well and I promise we will hunt together, and it will sound like Thor is there with us."

Olafrs eyes no longer glow, a fire has been lit and it burns strong. We go through the rest of the details and the feel in things. How there should be a piece of shaped flint clamped in leather there, and it should give good sparks down in the pan when it is released. That the parts shape, hardening and spring strength are important for there to be good sparks in a quick reaction, and he can try different patterns too. We talk about the safety and the feel of the trigger and its force. I point out the rain protection on the various parts. About simple screws to hold certain parts together so it can be loosened for maintenance. That the lower barrel in a double barrel gun should be slightly narrower in front, while the upper one should be straight, if it is possible to do, but not important.

Olafr can not say when it will be finished but it will be done as good as he can, even the mirrored mechanism. He looks forward to trying to make a sufficiently long narrow round pipe for the barrel. It is an interesting and difficult challenge, and we discuss a couple of ways to do it, including a rifled barrel as on the drawing for the rifle. The first thing he will build is basically a flintlock musket, but he gets to practice and see if he can make the flintlock and the barrel, and I understand if Olafr wants proof that my sejd works. I give Olafr all the drawings, even on wooden stocks and simpler sketches of a lathe and barrel drilling machine, rifling reamer, etc.

Its been more than an hour since we started talking about thunder weapons when I leave Olafrs smithy, and most of my company have been waiting in the carriage. The carriage really impresses Olafr, but he refuses to get too close as dirty as he is, and he shouts at an apprentices to ready two of his horses to accompany us to the ship to pick up the very valuable steel lumps. Olafr whisper that he will send a messengers to deliver to the island when the first object is ready, or if he cannot do the job well enough, and he will make those folding objects too.

I have never hunted animals. I have never wanted to it even though hunting is common where I live, and I grew up with a father who hunted and slaughtered the animal back home. But I look forward to trying Olafrs craft and accompanying him on a hunting trip.

The blacksmith who's worked on the steam boiler has finished it and will deliver the steam boiler to my boat. The steam boiler should only have to withstand low pressure so I'm not particularly worried, but he has done a good enough job that I order a new and smaller steam boiler for my future steam engine test. It is also a standing model but with the fire inside the steam boiler, which makes it more complex to manufacture, and the new steam boiler will have to withstand higher pressures too. It will still be a low pressure boiler and probably something like first half of 1800s. I hope the steam boiler will be able to handle 4-5 bar, and it will have reinforcement rings shrunk around, and plenty of folded edges and rivets where heat shrinkage can not be used. The chimney on the other hand, will be screwed on with many screws because there will be no high pressure there, just very hot, and I will make the threads myself. A removable chimney together with a small hatch in the tank also helps with maintenance. The hatch will be angled in and fastened with bolts from the outside, so pressure will force it closed, instead of relying on the bolts.

The last complication is that this boiler will be used with steam engines, so I want dry steam, and the boiler gets a simpler intake cylinder in the top, instead of just having outlet pipes. This boiler will also use a circulating water system via a condenser and the blacksmith will make that too. Steam injectors and other things like that will be a future problem.

Mercury and thoughts about it have made me realise how often I will need to create a vacuum in the future, especially a good vacuum if I want to make stuff like vacuum tubes and possibly light bulbs. That require a good low pressure. But falling mercury is a bad impractical solution for creating a vacuum even though is should create a good vacuum. At the same time I will probably have a functioning line shaft system and a steam engine in the near future. So I will try to build a rotating molecular vacuum pump. It doesn't need to be perfect or be able to achive a high vacuum as long as it works as a faster first step in making a vacuum.

A visit to Digraldi means that he takes on the task of creating the pump housing etc, but I will have to use a lathe and turn and balance the parts. The tolerances will be tight which means it will be hard to do. It will be interesting to see if mercury or oil works best as the liquid in the vacuum pump. And I have to make some kind of meter how good the vacuum is, which will be really hard as the vacuum gets higher.

Since the water filters have been a hassle and are bothersome, I will try with a sand filter, so Digraldi will make high and fairly wide containers for it.

I wonder how many concurrent projects I have going?