Stepping Back in Time…

As you can see in front of you, the 19th-century glasshouse complex is now in ruins. It’s difficult to imagine how it would have looked back in its heyday; this illustration helps give some idea. Stand as close as you can to the sign, and try to line up the chimneys.

It would have been filled with exotic, tender plants, needing the protection of a heated glasshouse. Taking a closer look, you can see it was an impressive structure divided into three compartments, each separated from another by an internal low wall, and heated by the cast iron heating pipe system, still clearly visible. This arrangement allowed for three different climatic regimes. The source of the heat was from the boiler situated behind the tall wall supporting the glasshouse, also known as the ‘spine’ wall. The compartment farthest from the heat source was used for dry-climate plants that only needed cooler conditions.  This one was used for grapevines. The compartment nearest the boiler, the hottest, and often called a ‘hot house’ or ‘stove house’. This house was kept humid using evaporated water from the narrow troughs atop the heating pipes; here equatorial plants were grown.

Each compartment’s heat could be regulated using valves on the heating pipes, and by opening or closing the side vents. As the heat circulated it cooled so the compartment farthest from the heat source was the coolest and used for dry climate plants which needed less intense heat, or just a frost free environment. The compartment nearest the heat source was the hottest and was often called a ‘stove house’ or hot house. This housed equatorial plants.

The middle compartment was a ‘plant house’ which housed various species of tender plants such as tropical orchids, ‘parlour’ palms and tropical ferns. Humidity was necessary for many of these plants and this was created by filling the narrow troughs atop the heating pipes with water which constantly evaporated and needed constant refilling. The Vinery was the coolest compartment and it would have been used to grow grapevines or tender flowering shrubs for display here or in the mansion house. Here the atmosphere was kept dry and well-ventilated so there was a good airflow to reduce damp muggy conditions.

There are two water tanks that ingeniously stored the rainwater coming off the roof gutters so that there was a ready supply of lime-free water kept at room temperature.  This ensured that delicate or lime-sensitive species were not subjected to cold limey water.



The glasshouses at Montalto are represented by several discrete structures, all now in a ruinous state and entirely roofless. The buildings belong to a number of distinct phases, though precise dates are not available. The main structure is represented by a long lean-to range, built in several phases, in a combination of local rubble stone and a variety of handmade and machined red brick. The glasshouses extended along the southern front of a spine wall, presumably presenting as a single range. On the north side of the wall there was a Potting Shed with a Stoke (Boiler) House combined in a deeper block at the western end. The old boiler is still in-situ. Although none of the roof structure survives, this north range was almost certainly slated, as per the OS maps and used for stores as well as the potting shed and boiler house. There may have been a bothy here also but not evident during the survey.



The main lean-to range was divided into three discrete compartments, the two at the western end of exactly the same size, 15ft x25ft, with the section at the eastern end slightly larger and associated with the vinery. The entire rear ( spine) wall was lime rendered originally, although the finish now survives only at the eastern end (with traces of its lime and raddle washes),  as do some of the rafters (though collapsed),  which implies that the vinery was maintained after the rest had fallen into disuse.



The outer walls of the glasshouse are formed as a double row of red brick, forming dwarf walls on which the timber superstructure rested. Although still largely concealed and overgrown, the outer walls of the vinery had openings which appear to be for the vines to pass through to the interior from their external planting positions in the vine border.

The internal divisions were also formed with brick dwarf walls, implying that the main division was formed as a glazed partition and that all of the sections were accessible internally. The main entrance was located in the western end wall, where the dressed stone cill survives. Inside, there is evidence for a paved floor of square quarry tiles, while in the adjoining section, a number of loose polygonal clay tiles (in imitation of Portland stone) and associated small square insets (in black) imply that the floor here was given a more elaborate treatment. The full extent of the floor treatment here should become apparent with further clearing of debris. Within these sections two dressed stone blocks survive on the ground, each carved with a square central socket; although displaced from their original positions, it is clear that these represent the base for vertical supports (presumably timber) likely used to support a purlin for the main rafters.



The Vinery is accessed by a door at the east of the main wall. Inside the vinery, the floor was paved with small red clay tiles, hexagonal in shape so as to produce a pleasing decorative pattern. At the western end, is a sunken heating trough covered with an ornamental cast-iron

grating, while most the floor space is taken up with two large brick-built water cisterns which collected and stored lime free rainwater and stored it at room temperature for watering. Grapevines were planted in the Vine Border (the area of ground outside the Vinery) This allowed their roots to spread and gave maximum feeding potential. The grapevine was inserted into the vinery through a dedicated opening at ground level in the glasshouse wall. Its branches were then trained onto a network of wires that were strung overhead and were vital to the successful cultivation and management of the vines. Grapevines required dry and cooler heat than tropical and equatorial plants so vineries were usually at the farthest end of the heat circulation from the boiler.


Heating System

The entire range, and the two adjoining pit houses, are served by a hot water system, evidently adapted over time as the houses were developed, and possibly replacing an earlier system though there is no clear evidence for this. A closed fireplace like recess in the wall of the potting shed at the western end, may relate to  an earlier stove or part of a warm air or flue system, though there is no evidence for any associated flues. In the lean-to range, a double row of twin four inch pipes are set side by side and extend  along the entire front of the three compartments, though unusually the pipes are set well back from the wall leaving a wide border which must have been difficult to access. The system was controlled at each of the junctions by valves, and the pipework was extended to each of the two pit houses, which had a double circuit of four-inch pipes placed around three walls. These pipes are remarkably well preserved.


Of particular interest are the troughs incorporated in the upper row of hot water pipes inside the westerly lean-to range. These shallow troughs were filled with water to cause evaporation to provide humidity in the atmosphere, which, with adequate ventilation, ensured the climatic conditions could be controlled and varied depending on the conditions required by specific plants. This aspect of the heating system in these two sections implies they were used specifically for tropical and equatorial plants, grown for their exotic flowers or foliage, rather than for fruit production.


Ventilation System

The ventilation required for each compartment varied according to its plant’s needs. Venting was done manually several times a day, using a system of levers to open and close vents in the side walls and roof. Doors also were opened or closed to help control heat loss and gain. Venting in response to fluctuations in weather conditions, wind and sunlight as well as peaks in the heat from the boiler was a constant battle to keep the ambient temperatures right. Any undergardener who failed in his task to keep heat regulated would certainly get in trouble.


Contents of Glasshouse

The glasshouse is divided into three separate compartments via internal doors, and the remains of the doorsteps can be clearly seen. This internal division gave a great opportunity to grow plants with particular temperature and humidity needs. The heating system circulated throughout the entire glasshouse but could be regulated with the valves and water troughs to create particular climatic conditions for specific groups of plants.  Apart from the grapevines, we can safely speculate that one compartment was a display house for tropical orchids, begonias, ferns, lilies, tender bulbs, streptocarpus, columnias, bromeliads, ‘parlour’ palms, and tender foliage plants were typical species used for display in the glasshouse and enjoyed in the reception rooms of the main house.


Spine Wall

The wall that divided the glasshouse from the potting shed, boiler and storerooms is built on an east-to-west orientation. This is so designed that the glasshouse avails of the full belt of sunlight while the potting shed, boiler/stoke shed and stores all face north, not to be seen or heard. So the family and their visitors were not treated to the view of the workings and workers but only saw the beautiful results of their toils.

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