Introduction
On 25 March, 1811, Victor Alaire, based in Paris, was awarded two five-year patents for his machine destined to cool and heat the interior of a carriage. The details of these two inventions appeared in the Description des Machines et Procédés spécifiés dans les brevets d'invention, de perfectionnement et d'importation, published by M. Christian in 1824, by which time the patents had expired.
Details of the two inventions
“Below the coachman's seat a ventilator is placed in such a way that it is activated by the movement of the smaller wheels at the front of the carriage, so that with each rotation of the wheels, a quantity of air equal to the capacity of the ventilator enters the carriage.
However, as in summer, the air surrounding the carriage is ordinarily full of dust, I first filter it through water before it enters the carriage.
If the water container through which the air passes before reaching the carriage is porous, such as the alcarrazas [an earthenware jug which keeps its contents cool by a process of evaporation] produced by M. Frémi – the water therefore being cooled using this method – then the air will also be [cool]; it will in any case be partly cooled if passed through ordinary water, due to the slight but continuous evaporation that this passage of air causes. If no porous vases can be had, or indeed for short journeys of a couple of hours, a basket of ice can be placed around the water receptical, thereby cooling and purifying the air.
The ventilator can be as large as the coachman's entire underseat; thus, with each rotation of the wheels, an immense quantity of air will be pushed into the carriage.
In every event, this air will always be extremely pure and slightly cooled, as it will have been filtered through water; it will also gain in freshness inside the carriage, simply due to its movement, as with a normal fan; it is thus possible, without depriving oneself of fresh air, to keep the windows shut, therefore protecting oneself from the heat and dust, and at the same time all the inconveniences that are experienced in a close, confined space during hot weather.
Instead of transforming the movement of the carriage's wheels, it can also be done using springs and gears.
[…]
Procedure in order to introduce warm air into carriages during winter
The air, rather than passing directly from the ventilator into the carriage, is firstly directed over lanterns which are ordinarily placed in traveling or city coaches; to this effect, the upper half of these lanterns is covered by two hemispherical caps, one set within the other, so that there is an interval of about two inches between the two rims. The lanterns' candle-flame is directed into the concave part of the cap and as the air is passed between the two covers, the time between each rotation of the ventilator is enough to heat the air that is pushed into the carriage to a temperature of thirty degrees […].
It is clear that, based on what has been already said, carriages with three lanterns will be heated far quicker than those with just two.
[The system] will be constructed so that an individual may, with a simple turn of a handle – similar to that of a musket bayonnet – close the hot air passage, which could prove inconvenient if allowed to continuously enter the carriage.”