Gradient Sentence Examples

The maximum gradient possible depends on climatic conditions, a dry climate being the most favourable.

The gradient below the mountains averages 7.5 ft.

Electrostatic fields come from a voltage gradient and can exist when charge carriers are stationary.

At any single station potential gradient has a wide range of values.

Single gradient lenses are shaded lighter on the bottom and darker on the top.

Rate at which work is done against a gradient.

The most elevated summits occur in the north, but even these are of very gentle gradient.

The steepest gradient is on the western main line.

The lens choices were gray, blue gradient, red gradient and brown..

Depending on the location, you may be able to choose from several other colors in addition to gray and brown, plus you can choose a gradient tint if you'd like.

He found the gradient nearly uniform for heights up to 30 to 40 metres above the ground.

A diminution in the number of positive ions would thus naturally be accompanied by a rise in potential gradient.

Sometimes, however, a sharp incline occurring on an otherwise easy line is not reckoned as the ruling gradient, trains heavier than could be drawn up it by a single engine being helped by an assistant or " bank " engine; sometimes also " momentum " or " velocity " grades, steeper than the ruling gradient, are permitted for short distances in cases where a train can approach at full speed and thus surmount them by the aid of its momentum.

Brunel laid out the Great Western for a long distance out of London with a ruling gradient of i in 1320.

In practice the gradient should not exceed i in 221, and even that is too steep, since theoretical conditions cannot always be realized; a wet rail will reduce the adhesion, and the gradients must be such that some paying load can be hauled in all weathers.

The Locher rack, employed on the Mount Pilatus railway, where the steepest gradient is nearly I in 2, is double, with vertical teeth on each side, while in the Strub rack, used on the Jungfrau line, the teeth are cut in the head of a rail of the ordinary Vignoles type.

The pull recorded on the diagram includes the resistances due to acceleration and to the gradient on which the train is moving.

Secondly, it must be able to maintain the train at a given speed against the total resistances of the level or up a gradient of given inclination.

Sometimes, as on the Central London railway, the acceleration of gravity is also utilized; the different stations stand, as it were, on the top of a hill, so that outgoing trains are aided at the start by having a slope to run down, while incoming ones are checked by the rising gradient they encounter.

On the margins of the plateau there are several gaps or indentations, which can best be likened to gigantic trenches, like railway cuttings, as with an insensible gradient they climb to a higher level.

Their power is proportioned to requirements of load and maximum gradient; the speed is rarely more than 6 or 8 m.

In driving mine passages thatj are to be used for drainage, care is taken to maintain sufficient gradient.

In a sheet-glass tank there is therefore a gradient of temperature and a continuous passage of material from the hotter end of the furnace where the raw materials are introduced to the cooler end where the glass, free from bubbles and raw material, is withdrawn by the gatherers.

Ignoring temperature effect, and taking the density as a function of the pressure, surfaces of equal pressure are also of equal density, and the fluid is stratified by surfaces orthogonal to the lines of force; n ap, dy, P d z, or X, Y, Z (4) are the partial differential coefficients of some function P, =fdplp, of x, y, z; so that X, Y, Z must be the partial differential coefficients of a potential -V, such that the force in any direction is the downward gradient of V; and then dP dV (5) ax + Tr=0, or P+V =constant, in which P may be called the hydrostatic head and V the head of potential.

Reynolds, in his investigation, introducing no new form of law of distribution of velocities, uses a linear quantity, proportional to the mean free path of the gaseous molecules, which he takes to represent (somewhat roughly) the average distance from which molecules directly affect, by their convection, the state of the medium; the gas not being uniform on account of the gradient of temperature, the change going on at each point is calculated from the elements contributed by the parts at this particular distance in all directions.

A gradient like this, only 1 in 1,350,000, could give rise only to an extremely feeble surface current polewards and an extremely feeble deep current towards the equator.

In the South Wales system of working, cross headings are driven from the main roads obliquely across the rise to get a sufficiently easy gradient for horse roads, and from these the stalls are opened out with a narrow entrance, in order to leave support on either side of the road, but afterwards widening to as great a breadth as the seam will allow, leaving pillars of a minimum thickness.

A road maybe used as a self-acting or gravitating incline when the gradient is r in 30 or steeper, in which case the train is lowered by a rope passing over a pulley or brake drum at the upper end, the return empty train being attached to the opposite end of the rope and hauled up by the descending load.

Where the load has to be hauled up a rising gradient, underground engines, driven by steam or compressed air or electric motors, are used.

In the simplest case, that of uniform translation, these components of the gradient will each be constant throughout the region; at a distant place in free aether where there is no motion, they must thus be equal to -u,-v,-w, as they refer to axes moving with the matter.

At Canyon City it passes out of the Rockies through the Grand Canyon of the Arkansas; then turning eastward, and soon a turbid, shallow stream, depositing its mountain detritus, it flows with steadily lessening gradient and velocity in a broad, meandering bed across the prairies and lowlands of eastern Colorado, Kansas, Oklahoma and Arkansas, shifting its direction sharply to the south-east in central Kansas.

Thus a fall in the gradient at any point in the course of a stream; any snag, projection or dam, impeding the current; the reduced velocity caused by the overflowing of streams in flood and the dissipation of their energy where they enter a lake or the sea, are all contributing causes to alluviation, or the deposition of streamborne sediment.

Since some ions are more mobile than others, a separation will ensue when water is placed in contact with a solution, the faster moving ion penetrating quicker into the water under the driving force of the osmotic pressure gradient.

Now the velocities u and v of the opposite ions under unit potential gradient, and therefore U and V under unit force, are known from electrical data.

The " gradient of temperature " is the fall of temperature in degrees per unit length along the lines of flow.

The thermal conductivity of the substance is the constant ratio of the rate of transmission to the temperature gradient.

If the gradient is not uniform, its value may be denoted by dB/dx.

In the steady state, the product kdO/dx must be constant, or the gradient must vary inversely as the conductivity, if the latter is a function of 0 or x.

The measurement of the temperature gradient in the plate generally presents the greatest difficulties.

The outward gradient is dO/dr, and is negative if the central hole is heated.

It is the most convenient method, in the case of good conductors, on account of the great facilities which it permits for the measurement of the temperature gradient at different points; but it has the disadvantage that the results depend almost entirely on a knowledge of the external heat loss or emissivity, or, in comparative experiments, on the assumption that it is the same in different cases.

C. Mitchell, under Tait's direction, repeated the experiments with the same bar nickel-plated, correcting the thermometers for stem-exposure, and also varying the conditions by cooling one end, so as to obtain a steeper gradient.

The gradient near the entrance to the calorimeter was deduced from observations with five thermometers at suitable intervals along the bar.

The heat transmitted through the plane x is equal per unit area of surface to the product of k by the mean temperature gradient (de /dx) and the interval of time, T - T'.

The mean temperature gradient is found by plotting the curves for each day from the daily observations.

The heat per second gained by conduction by an element dx of the bar, of conductivity k and cross section q, at a point where the gradient is dB/dx, may be written gk(d 2 6/dx 2)dx.

The chief difficulty, as usual, was the determination of the gradient, which depended on a difference of potential of the order of 20 microvolts between two junctions inserted in small holes 2 cms. apart in a bar 1 .

It was also tacitly assumed that the thermo-electric power of the couples for the gradient was the same as that of the couples for the mean temperature, although the temperatures were different.

Owing to the difficulty of measuring the gradient, the order of divergence of individual observations averaged 2 or 3%, but occasionally reached 5 or io %.

The magnitude of the stress per unit area parallel to the direction of flow is evidently proportional to the velocity gradient, or the rate of change of velocity per cm.

Similarly if A is hotter than B, or if there is a gradient of temperature between adjacent layers, the diffusion of molecules from A to B tends to equalize the temperatures, or to conduct heat through the gas at a rate proportional to the temperature gradient, and depending also on the rate of interchange of molecules in the same way as the viscosity effect.

These Losses Were As Far As Possible Eliminated By Combining The Trials In Pairs, With Differ Ent Loads On The Brake, Assuming That The Heat Loss Would Be The Same In The Heavy And Light Trials, Provided That The External Temperature And The Gradient In The Shaft, As Estimated From The Temperature Of The Bearings, Were The Same.

This is called the curve of positions or space-time curve; its gradient represents the velocity.

This has a great volume of water, but is unnavigable because of its steep gradient and many gorges.

The normal seasonal march of pressure-change produces a maximum gradient in December and January, and a minimum gradient in April; but for every month in the year the mean gradient is for winds from southerly and westerly quarters.

In April the gradient is so slight that any temporary fall of pressure to the south of England or any temporary rise of pressure to the north, which would suffice in other months merely to reduce the velocity of the south-westerly wind, is sufficient in that month to reverse the gradient and produce an east wind over the whole country.

Since the only cause for these convection currents is the statical instability produced by radiation, and the rapid stifling of radiations within the body produces there a temperature gradient falling very slowly, they would be for the most part extremely slight.

The temperature gradient at the confines of the photosphere must certainly ascend sharply at first.

The whole diagram shows, by the greater gradient of the unbroken straight lines, the greater demand which can be satisfied by the enlargement of the reservoir to the extent necessary to equalize the flow of the two driest consecutive years.

From the overflow sill the bye-wash channel may be gradually narrowed as the crest of the embankment is passed, the water being prevented from attaining undue velocity by steps of heavy masonry, or, where the gradient is not very steep, by irregularly set masonry.

For simplicity in the diagram the temperature gradient has been taken as uniform, and the specific heat s= constant, but the total P.D.

As an example of advection let us consider 1D advection of a constant gradient of some scalar.

The solubilized mixture was then resolved by sucrose density gradient centrifugation.

After density gradient centrifugation, virus particles were detected in the density zone of 1.34 g/ml.

The low conductivity of char will cause a steep thermal gradient across the char layer.

The bacterial flagellum is driven by a proton motive force resulting from a gradient of protons.

One involves experimental and numerical research into the behavior of liquid gallium under the combined action of a temperature gradient and a magnetic field.

This is because the gradient of a curve at a point is equal to the gradient of the tangent at that point.

There is a steep social class gradient in deaths from suicide.

The uncoupling protein blocks development of a H + electrochemical gradient, thereby stimulating respiration.

It is noted that both the initial states have interior reversals in the sign of the latitudinal gradient of PV on isentropic surfaces.

For one-dimensional flow, constant flow rate implies constant hydraulic gradient.

The second day provided us with an opportunity to observe the altitudinal vegetation gradient on a south to north transect, ending in Pucon.

These enzymes pump protons across the inner membrane, building up a proton gradient.

The water salinity; The lagoon shows a unique salinity gradient from Smallmouth to Abbotsbury.

The electrical gradient drives cation uptake, while the pH gradient powers cation export.

These minerals are absorbed against the concentration gradient, from a dilute solution in the soil water into the concentration solution in the cells.

There also exists a temperature gradient from the bore to the rim of the disk.

There is a slight uphill gradient, and a tiny handful of buildings appear on the skyline.

The contour interval is a bit wide but there are plenty of gradient arrows on the comprehensive network of highlighted cycle routes.

This generates a proton gradient across the thylakoid membrane.

We have managed to explain, and quantify, the origin of the surprising negative gradient of the bulk modulus in this model.

Unlike conventional molding, you are not pressurizing a local gradient area of the machine platen attempting to pack out the part.

A gradient equivalent to an activation energy of 300 kJ mole -1 is shown superimposed on the data.

Identify similar chemicals as the major precipitant, and alter them in a gradient.

Pressure was 1008 mb still within a slack pressure gradient keeping winds light through the day.

The rates of pore fluid flow are related to the pore pressure gradient through Darcy's Law.

These enzymes pump protons across the inner membrane, building up a protons across the inner membrane, building up a proton gradient.

The first bit had a gentle gradient but was quite badly rutted, catching out Mike Hobbs in his Big Beetle.

The gradient steepened in the last few hundred yards and in addition there was a very sharp right hand curve.

So, all we need to do is construct the tangent and measure its gradient, δ y / δ x.

An enclosed vivarium is unsuitable for any species that requires a temperature gradient, or differential, to enable self-selection of body temperature.

The heat loss through the cylinder wall leads to a significant temperature gradient in the boundary layer.

Additionally the mean temperature gradient after cold exposure was reduced after laser irradiation, while the number of fingers showing prolonged rewarming was unaffected.

Vector quantities, for which both magnitude and direction are required, such as temperature gradient, are first rank tensors.

Can either use a large gradient or a critical value of PV to define the tropopause; it depends what you are looking at!

The round course contains significant undulations and there is quite a change in gradient up the straight.

For example, a recent analysis of the socioeconomic patterning of women's health found that psychosocial well-being displayed the steepest socioeconomic gradient.

A line is described by its gradient and intercept, the point at which the line crosses the y-axis.

With a view to this, it has become increasingly common of late years to publish not the voltages actually observed, but values deduced from them for the potential gradient in the open in volts per metre.

From the European data one would be disposed to conclude that [[Table Ii]].-Diurnal Variation Potential Gradient.

The formula makes the gradient diminish from 25 volts per metre at 1500 metres height to To volts per metre at 4000 metres.

If the mean of the gradients observed at the ground and at 1500 metres be taken as an approximation to the mean value of the gradient throughout the lowest 1500 metres of the atmosphere, we find for the potential at 1500 metres level 112,500 volts.

Elster and Geitel found the sign of the charge often fluctuate repeatedly during a single rain storm, but it seemed more often than not opposite to that of the simultaneous potential gradient.

At KremsmunsterZolss (41) finds a considerable similarity between the diurnal variations in q and in the potential gradient, the hours of the forenoon and afternoon maxima being nearly the same in the two cases.

At Karasjok Simpson (10) found fairly similar mean values of A for two groups of observations, one confined to cases when the potential gradient exceeded +400 volts, the other confined to cases of negative gradient.

South of this anticyclone, from about the latitude of the Cape, we find the region where, on account of the uninterrupted sea surface right round the globe, the planetary circulation is developed to the greatest extent known; the pressure gradient is steep, and the region is swept continuously by strong westerly winds - the " roaring forties."

A cutting, or cut, is simply a trench dug in a hill or piece of rising ground, wide enough at the bottom to accommodate one or more pairs of rails, and deep enough to enable the line to continue its course on the level or on a moderate gradient.

The ruling gradient of the Liverpool & Manchester railway was fixed at r in coo, excepting the inclines at Liverpool and at Rainhill summit, for working which special provision was made; and I.

If the train is running down a gradient this horse-power is the rate at which gravity is working on the train, so that with the data of the previous section, on the assumption that the train is running down a gradient of I in 300, the horse-power required to maintain the speed would be 354-223=131.

If the starting resistance of the whole train be estimated at 16 lb per ton, this engine would be able to start 1.163 tons on the level, or about 400 tons on a gradient of I in 75, both these figures including the weight of the engine and tender, which would be about 100 tons.

He assumed that the distribution of molecules and of their velocities, at each point, was slightly modified, from the exponential law belonging to a uniform condition, by the gradient of temperature in the gas (see Diffusion).

According to Maxwell, priority in showing the necessity for slipping over the boundary rests with Reynolds, who also discovered the cognate fact of thermal transpiration, meaning thereby that gas travels up the gradient of temperature in a capillary tube, owing to surface-actions, until it establishes such a gradient of pressure (extremely minute) as will prevent further flow.

They are preceded by a rapid fall of the barometer for about a day, until a gradient from south to north is formed, then the wind commences to blow, at first gently, from the south-east; rapidly increasing in violence, it shifts through south to south-west, finally dropping about sunset.

The river enlarged the canal, and finding a steeper gradient than that to its mouth, was diverted into the Colorado desert, flooding Salton Sea; 1 and when the break in this river was closed for the second time in February 1907, though much of its water still escaped through minor channels and by seepage, a lake more than 400 sq.

Telford realigned the turnpike road substantially to even out the gradient.

This has successfully reduced the septal thickness and the outflow tract gradient.

There was little evidence of a socioeconomic gradient in survival.

The lowest gears may only be necessary if the vehicle is loaded or when you are climbing a steep gradient.

In either case the growing disturbances will tend to erode the gradient that is producing them, namely the temperature gradient.

At the same time, the protein pumps protons across the membrane generating a transmembrane gradient.

To the west of the platforms are a trio of sidings which are situated on a gradual gradient, relative to the platform lines.

Can either use a large gradient or a critical value of PV to define the tropopause; it depends what you are looking at !

Over the thickness of the fluid there is a velocity gradient depending on the relative movement of the bearing surfaces.

A vernier style adjustment system ensures the ladder foot is secure whatever the gradient.

For example, a recent analysis of the socioeconomic patterning of women 's health found that psychosocial well-being displayed the steepest socioeconomic gradient.

This is turn sets up a concentration gradient across which water moves by osmosis out of the xylem cells and across the leaf.

A smoky style means you have a gradient from dark to light, starting at the lashes and going up to the brow bone.

Scratch resistant coatings, gradient lenses, and mirror or flash coatings are available in a variety of styles.

You can also get this style in Black on Black Stripe Frame/Smoke, Blue on Red Frame/Brown Gradient, or Black on Black Stripe Frame/Polarized lenses.

They have a shiny black frame and blue gradient lenses.

Other color schemes include Midnight Black/Navy Gradient and Shiny Black/Smoke Gray Polarized.

Also, you'll want to ask for a gradient tint so that the bifocal lenses will be darker at the top and get lighter toward the bottom.

There is currently not a gradient tint option.

This pair has a gradient tint so it's easier to read maps and then look back up again at the road without eyestrain.

Double gradient lenses, which are dark on top and bottom and lighter in the middle of the lens, are recommended for sports where a high degree of glare reflection occurs, such as skiing.

The Dior Air 1 is a delicate pair with gradient tint.

The brown and gold pair features a gradual brown gradient lens, but both pairs are available for $344.99.

You can also get those three types of lenses in traditional, amber or gradient sets.

The important part, however, is why to look for gradient lenses specifically.

Gradient lenses are typically tinted so that the deepest color is at the top, fading gradually down to clear or nearly clear at the bottom.

They're made up of a silver frame that hugs the brown gradient lenses.

The frame is, of course, silver, and the lenses are a beautiful gradient plum.

This pair has a gunmetal frame with pink gradient lenses.

This style even has gradient lenses for an ultra chic look.

The lens on the Black Pearl frame is a black gradient.

The Navy Ivory frame has a lens with a gray gradient and is lightweight in design and feel.

The brown gradient lens only adds to the allure and drama of the look.

Note that the lenses here too are of a subtle brown gradient.

The Complot features the well-known LV monogram on the frame, gradient, slightly rectangular lenses, and gold accents.

Choose from Smoke or Amber Gradient lenses, 2.5x or 3.5x magnification.

Check out the lavender gradient lenses of the partly rimless MJ 050 Silver.

These aren't to be confused with gradient lenses.

They enhance your vision and have an amber gradient tint that reduces glare as well as sharpens your vision.

The gradient design of the lenses will allow you to keep your glasses on all the time instead of struggling to keep up with a pair of readers as you go from one activity to the next, and back again.

They're available in five different color combinations, some of which include Polished Gold/Brown Gradient, Midnight Blue/Grey, and Berry/Black.

You can get these for $375.00 in brownstone horn with spice brown, black with grey gradient, or sycamore/oyster pearl with amber bronze.

A wide range of lens colours is available, along with gradient tints.

The lens is done in a gradient grey, so it varies from almost clear to a slightly smoky look in appearance, while the overall frames are silver.

This is a good thing because it allows the gradient brown lens to pop with color.

In addition to the elegant and chicly sleek arms in the gradient brown lens, this lens color, when paired with the arm temples, provides a stunning, fashionable look.

This one is available in light Havana/brown gradient, silver/black Saffiano gray, brown camel/brown gradient, Havana brown, and shiny gunmetal/gray gradient.

Mirrored coatings used to be primarily silver for many years, but today you can get mirrored coatings in a wide variety of fun colors like pink, orange or even a gradient of color from top to bottom.

For those looking for a great pair of purple shades, choose the Blush frames with Black Gradient lens.

All are UV-400 rated, and styles offering polarization, gradient lenses, mirror finish, and other specific characteristics are available.

Glasses similar to those above but with a gradient tint, darker at the top and close to clear at the bottom.

There is also a number of sunglass features such as anti-reflective coatings, ClearSeal protective coatings, gradient lenses, polarized lenses, and selective filtering lenses designed to increase contrast.

Multiple color and tint gradient choices (mauve, brown, blue, yellow, gray, clear, etc.) for different conditions, including low light, glare reduction, clarity enhancing, and color preservation options.

Gradient lenses are permanently shaded from top to bottom, or from top and bottom toward the middle.

Double gradient lenses are darker on top and bottom, and lighter in the middle.

Wraparounds, fitovers, polarized and gradient lenses offer an extra layer of defense.

The optical lab then tints your lenses as you wish--from a gradient that starts darker on top and gets lighter toward the bottom (great for simultaneous map reading and driving), to one solid color in any depth.

A gradient lens and a cool toned metal look complete the design.

A gradient lens of brown or grey first greets the wearer, while the gently tapered frame provides comfort.

Violet gradient lenses are set in a violet metal frame with the Chanel logo on both the temple and nose pads.

Color choices include copper frame/brown gradient lens, gold frame/brown gradient lens, and rhodium frame/smoke gradient lens.

Options include an antique frame/brown-green gradient flash, gold frame/gold flash lens, rhodium frame/light blue flash lens, and rose frame/burgundy flash lens.

Color choices include black frame/silver flash lens, bronze frame/brown gradient lens, copper frame/brown-peach gradient lens, gold frame/brown gradient lens, gunmetal frame/smoke gradient lens.

Frame colors included black, bronze, blue smoke and red gradient.

The Sedona lens blocks glare and features a double gradient mirror design.

Serengeti 7021 Classics Paolo Satin have gradient lenses and a Satin Espresso frame.

The logos are simply serif-fonts with a gradient image emblazoned between the words.

Papers with gradient colors can give your project a very realistic appearance when folding flowers.

There is a gradient of just how free Christian Internet dating services are.

From observations during twelve balloon ascents, Linke concludes that below the 1500-metre level there are numerous sources of disturbance, the gradient at any given height varying much from day to day and hour to hour; but at greater heights there is much more uniformity.

At most stations a negative potential gradient is exceptional, unless during rain or thunder.

Taking their origin from a series of lacustrine basins scattered over the plateaus and differing slightly in elevation, the Russian rivers describe immense curves before reaching the sea, and flow with a very gentle gradient, while numerous large tributaries collect their waters from over vast areas.

Dvina flows with a very slight gradient through a broad valley, and reaches the White Sea at Archangel.

The gradient or grade of a line is the rate at which it rises or falls, above or below the horizontal, and is expressed by stating either the horizontal distance in which the change of level amounts to r ft., or the amount of change that would occur in some selected distance, such as roo ft., r000 ft.

In America a gradient of r in roo is often known as a r% grade, one of 2 in roo as a 2% grade, and so on; thus a 0-25% grade corresponds to what in England would be known as a gradient of r in 400.

The ruling gradient of a section of railway is the steepest incline in that section, and is so called because it governs or rules the maximum load that can be placed behind an engine working over that portion of line.

The lines through them should be, if possible, straight and on the level; the British Board of Trade forbids them being placed on a gradient steeper than i in 260, unless it is unavoidable.

These considerations also indicate what a difficult matter it is to find the exact rate of working against the resistances, because of the difficulty of securing conditions which eliminate the effect both of the gradient and of acceleration.

At a distance from the central core the radiating ridges become less abrupt and descend with a gentle gradient, finally passing somewhat abruptly, at a height of some 7000 ft., into the level plateau.

The bridle road up the mountain leaves Glen Nevis at Achintee; it has a gradient nowhere exceeding 1 in 5, and the ascent is commonly effected in two to three hours.

The slope then steepens with the ascending curve to the summit of the pass, from which point it falls with a comparatively gentle gradient to the general level of the plateau.

In this table, unlike Table IV., amplitudes are all expressed as decimals of the mean value of the potential gradient for the corresponding season.

Some of the earliest balloon observations made the gradient increase with the height, but such a result is now regarded as abnormal.

Table Potential, Dissipation, Ioniz If we regard the potential gradient near the ground as representing a negative charge on the earth, then if the source of supply of that charge is unaffected the gradient will rise and become high when the operations by which discharge is promoted slacken their activity.

Thus a gradient of I in 200 is the same as a half per cent.

There must, then, be a relation between the rate of change of the concentration and the osmotic pressure gradient, and thus we may consider the osmotic pressure gradient as a force driving the solute through a viscous medium.

Our internal electrical system works by using cells that have built up electrical gradient or energy that can be given off to other cells by direct transfer.

Above the level plain of absolutely smooth surface, devoid of houses or vegetation, the equipotential surfaces under normal conditions would be strictly horizontal, and if we could determine the potential at one metre above the ground we should have a definite measure of the potential gradient at the earth's surface.

The potential gradient near the ground varies with the season of the year and the hour of the day, and is largely dependent on the weather conditions.

The first line gives the mean value of the potential gradient, the second the mean excess of the largest over the smallest hourly value on individual days.

It will be noticed that the difference between the greatest and least hourly values is, in all but three winter months, actually larger than the mean value of the potential gradient for the day; it bears to the range of the regular diurnal inequality a ratio varying from 2.0 in May to 3.6 in November.

The potential difference between the two is recorded, and the potential gradient is thus found.

In some localities, however, negative potential gradient is by no means uncommon, at least at some seasons, in the absence of rain.

Lenard, Elster and Geitel, and others have found the potential gradient negative near waterfalls, the influence sometimes extending to a considerable distance.

No distinct relationship has yet been established between potential gradient and radioactivity.

Beyond this parallel the gradient is directed towards the north-west, and temperatures are much higher on the European than on the American side.

This distribution is most marked at about 300 fathoms, and disappears at soo fathoms, beyond which depth the lines tend to become parallel and to run east and west, the gradient slowly diminishing.

It was not till more than half a century later that an American, Sylvester Marsh, employed the rack system for the purpose of enabling trains to surmount steep slopes on the Mount Washington railway, where the maximum gradient was nearly 1 in 22.

The large difference between the means obtained at Potsdam and Kremsmtinster, as compared to the comparative similarity between the results for Kew and Karasjok, suggests that the mean value of the potential gradient may be much more dependent on local conditions than on difference of latitude.

Hence if a train is travelling up the gradient at a speed of V ft.

Hence the absolute velocities of the two ions can be determined, and we can calculate the actual speed with which a certain ion moves through a given liquid under the action of a given potential gradient or electromotive force.

First, it must be able to exert a tractive force sufficient to start the train under the worst conditions possible on the railway over which it is to operate - for instance, when the train is stopped by signal on a rising gradient where the track is curved and fitted with a guard-rail.