Good question,
I assume the reason why most liquid AH's you see today have canted glass elements is to reduce the possibility of refraction. Ideally both the observer and the angle of the sun will be close to perpendicular to these plastic or glass elements. However, there is such a thing as optically true transparent materials such as camera filters and such. These might offer the least chance of distortion.
I'm currently seeking a source of mercury. Easier to keep than oil or syrup and better able to withstand rippling from a breeze, mercury dates back to at least lewis and clark and probably further. I'm also investigating the use of a mirror as an AH. silvering the top like a reflector telescope rather than from behind the glass like a shaving mirror illiminates glass distortion. How to level would be the big question.
I'm sure others have more concrete thoughts than my own.
I assume the reason why most liquid AH's you see today have canted glass elements is to reduce the possibility of refraction. Ideally both the observer and the angle of the sun will be close to perpendicular to these plastic or glass elements. However, there is such a thing as optically true transparent materials such as camera filters and such. These might offer the least chance of distortion.
I'm currently seeking a source of mercury. Easier to keep than oil or syrup and better able to withstand rippling from a breeze, mercury dates back to at least lewis and clark and probably further. I'm also investigating the use of a mirror as an AH. silvering the top like a reflector telescope rather than from behind the glass like a shaving mirror illiminates glass distortion. How to level would be the big question.
I'm sure others have more concrete thoughts than my own.