Ventilation will still require constant care.
Abundant means of ventilation should be provided.
Ventilation is provided at sides and top.
When a number of specimens have to be submitted to pressure, ventilation is secured by means of frames corresponding in size to the drying paper, and composed of strips of wood or wires.
And with the means of giving sufficient ventilation to keep the air sweet.
For reasons of health it may be assumed that no system of heating is advisable which does not provide for a constant renewal of the air in the locality warmed.
In a mine with shafts opening at the same level, natural ventilation once established will be effective during cold weather, as the downcast will have the temperature of the outside air, while the upcast will be filled with the warm air of the mine.
Ventilation may be produced by heating the air of the mine, as for example, by constructing a ventilating furnace at the bottom of an air shaft.
The use of two independent connexions - whether separate pits or sections of the same pit, between the surface and the workings - is necessary for the service of the ventilation, fresh air from the surface being carried down one, known as the " downcast," while the foul or return air of the mine rises through the other or " upcast " pit back to the surface.
The character of such workings is very irregular in plan, and as the ventilation is attended with considerable difficulty, it is now becoming generally superseded by more improved methods.
This system, therefore, combines both methods of longwall working, but it is not generally applicable, owing to the difficulty of ventilation, due to the great length of air-way that has to be kept open around the waste on each bank.
One of the most important branches of colliery work is the management of the ventilation, involving as it does the supply of fresh air to the men working in the pit, as well as the removal of inflammable gases that may be given off by the coal.
The size of the grate varies with the requirements of the ventilation, but from 6 to io ft.
Release of stored-up masses in the coal, which, overpowering the ventilation, produce magazines of explosive material ready for ignition when brought in contact with the flame of a lamp or the blast of a shot.
The ventilation of ends is effected by means of brattices or temporary partitions of thin boards placed midway in the drift, and extending to within a few feet of the face.
Franklin's advocacy of vegetarianism, of sparing and simple diet, and of temperance in the use of liquors, and of proper ventilation has already been referred to.
Good ventilation is indispensable to allow the worm to give out by transpiration the great quantity of water that it absorbs with the leaf.
There are no upright front sashes, but to facilitate ventilation there are ventilators d in the front wall, and the upper roof sashes are made to move up to FIG.
This consists mainly in the storing only of such fruits as are dry and in proper condition; in judicious ventilation, especially in the presence of large quantities of newlygathered fruit; in the prompt removal of all decaying fruit; and in the exclusion of vermin.
Means of affording ventilation in all plant houses should be provided in at least two places - as near the floor as practicable, and at the top. Mechanical contrivances whereby whole sets of ventilators may be operated simultaneously are now in common use, and are much more convenient and economical than the older method of working each ventilator separately.
The house should be opened for ventilation in all mild weather in winter, and daily throughout the rest of the year.
Under such conditions work would be practically impossible except with very energetic ventilation and dry air.
The principal publications on heating are: Hood, Practical Treatise on Warming Buildings by Hot Water; Baldwin, Hot Water Heating and Fittings; Baldwin, Steam Heating for Buildings; Billings, Ventilation and Heating; Carpenter, Heating and Ventilating Buildings; Jones, Heating by Hot Water, Ventilation and Hot Water Supply; Dye, Hot Water Supply.
They assist in the extremely rapid and vigorous ventilation of the lungs, the latter being capable of but very limited expansion and contraction in birds.
The latter includes not only the actual excavation of the mineral, but also haulage and hoisting by which it is brought to the surface, timbering and other means of supporting the excavations, and the drainage and ventilation of mines.
As already noted large pillars must always be left to protect shafts, adits and the more important mine-passages necessary for drainage, ventilation and the haulage of mineral.
These winzes serve for ventilation, for the passage of the workmen, and for chutes through which the ore is dumped to the level below.
The terrible effects of fire-damp have led to the adoption of elaborate systems of ventilation, as the most effective safeguard against these explosions is the dilution and removal of the fire-damp as promptly and completely as possible.
In metal mines, however, artificial ventilation is rarely attempted, and natural ventilation often fails to furnish a sufficient quantity of air.
More effective ventilation will materially lessen the deathrate.
As much ventilation as the state of the weather will permit should be given.
Such currents, due to the banking up of water, have a large share in setting the depths of the sea in motion, and so securing the vertical circulation and ventilation of the ocean.
The ventilation of pillar working is often attended with difficulty, and the coal is longer exposed to the influence of the air, a point of importance in some coals, which deteriorate in quality when exposed to a hot damp atmosphere.
The main level or gate road is driven in the benches coal, or lower part of the seam, while a smaller drift for ventilation, called an air heading, is carried above it in one of the upper beds called the slipper coal.
Plant houses must be as far as possible impervious to wet and cold air from the exterior, provision at the same time being made for ventilation, while the escape of warm air from the interior must also be under control.
In this house the principal part of the roof is a fixture, ventilation being provided for by small lifting sashes against the back wall, and by the upright front sashes being hung on a pivot so as to swing outwards on the lower side.
For many plants this under current of ventilation would be exceedingly beneficial, especially when cold winds prevented the sashes from being opened.
It is important that the ventilation should be as efficient as practicable, especially where coke fuel is to be used.
In summer the temperature may range to° higher by artificial heat, night and day, and will often by sun heat run up to 90° or even 95°, beyond which it should be kept down by ventilation and frequent syringing and damping down of the pathways.
- Ventilation will be necessary to keep down excessive heat; and attention must be paid to potting, shifting and putting in cuttings, and giving abundance of water to the potted plants, both indoors and out.
Keep up moderate temperatures in the stove, and merely repel frosts in the greenhouse, guarding against damp, by ventilation and by the cautious use of water.
If roots have been placed in cellars, attention must be given to ventilation, which can be done by making a wooden box, say 6 by 8 in., to run from the ceiling of the cellar to the eaves of the building above.
The primary causes of decay in timber are the presence of sap, exposure to conditions alternately wet and dry, and want of efficient ventilation, especially if accompanied by a Timber.
6 a may result, a point of extreme importance in connexion with the lighting and ventilation of dwellings, the purification of rivers and streams, and the general diminution of epidemics in nature.
This board is required to visit each of the institutions at least once a year to ascertain its condition and needs, and all proposed appropriations for their support, plans of buildings, proposed systems of sewerage, ventilation and heating must be submitted to it.
Wherever possible the lines were constructed in open cutting, to ensure adequate ventilation; and where this was not possible they were built by a method suggestively named " cut and cover."
Striking the shafts of the Comstock Lode, securing ventilation and cool air for the miners, draining the mines above its level, and obviating much pumping and hoisting.'
The ventilation of a mine must in general be produced artificially.
When the temperature of outside and inside air becomes equal or nearly so natural ventilation ceases or becomes insignificant.
Natural ventilation is impracticable in flat deposits worked by drifts and without shafts.
In this portion of the pit are generally placed the furnaces for ventilation, and the boilers required for working steam engines underground, as well as the stables and lamp cabin.
Mechanical ventilation may be effected either by direct exhaustion or centrifugal displacement of the air to be removed.
Ventilation is afforded at the ends, usually by tilting laths, operated by a cord.
In addition to this it is desirable to take advantage of the natural ventilation, that is, to circulate the air in the direction that it goes naturally, as otherwise the resistance to the movement of the air may be greatly increased.