Shade Temperature Research Articles

The heating of cables exposed to the sun in racks

In general, the temperature-rise of the surface of a cable, freely exposed to the air, due to the current carried, will only be a few degrees above ambient temperature, whereas if the cable is exposed to direct sunlight a substantial increase of temperature will occur. This increase may be treated as additional to that due to the load, provided it is noted, in calculating the former, that the resistance will be increased at the higher temperature reached by exposure to the sun.It is found that this rise is brought about in part by radiation, but mainly by convection. It therefore varies with the intensity of the solar radiation, the velocity of the ambient air, the diameter of the cable, its location (i.e. the extent to which it is exposed), and the nature of the surface of the cable.The maximum solar radiation in different parts of the world is known approximately, and some tabular information is given in the paper. From this the temperature-rise of a cable of given diameter can be determined for a given air velocity by means of a factorF varying with the diameter of the cable and with the air velocity. It is found, further, that there is in practice an approximate minimum air velocity, and the maximum rise is tabulated for this figure.This maximum will be attained in about half an hour, and will be reached if the sky is clear and the cable is directly exposed normal to the sun's radiation between, say, 12 noon and 2 p.m. Summer Time.Under these conditions cables of 2 to 2½ in diameter,in this country, may show a temperature-rise of 17 deg.C. This figure must be deducted from the permissible rise of, say, 50 deg. C. above shade temperature, thus materially reducing the rating of the cable.The data given are based on results obtained in London, Milan and Buenos Aires, and are in good agreement.An account is given of the methods employed and results obtained, together with supplementary information on certain technical features that presented difficulty during the investigation.

Status of Economic Entomology in the British Solomon Islands

The Solomon Islands lie to the east of New Guinea and consist of an archipelago a thousand miles in length and about half this distance in breadth. They are divided politically into the Northern Solomons (formerly German but now administered under Mandate by Australia), and the British Solomon Islands Protectorate. This latter lies roughly between five and twelve degrees south of the equator and is believed to have been united both to New Guinea and Australia from at least the Triassic to the early Tertiary. As there is now a deep sea between the archipelago and the two land-masses, the former falls into the ancient section of the continental islands of Wallace.The rainfall averages 150 inches, the maximum shade temperature has a mean of 90°F., and the relative atmospheric humidity averages 92 per cent.The Group consists of six large islands ranging from 60 to 120 miles in length and many smaller ones, including the isolated Santa Cruz group to the east. The main islands are composed of both coralline and volcanic (chiefly diorite) rocks and hence exhibit a wide range of soil-types from coralline sands and red clay to alluvium. Evidence of former extensive elevation is provided in raised coral-beaches. The islands are generally covered with jungle and densely wooded to their summits which rise in places to over 8,000 feet. An exception to this is the central and western portions of the northern coast of Guadalcanal, which consist of grass plains and undulating downland.

FUSARIUM SPECIES ON BRITISH CEREALS: FUSABIUM NIVALE (FR.) CES. (=?CALONECTBIA GRAMINICOLA (BERK. & BR.) WR.)

SUMMARY.1. F. nivale (?Calonectria graminicola) was commonly present along with one or more other species of Fusarium on the basal parts of oats and perennial rye‐grass that had failed in a field. The pathogenicity of the other species of Fusarium being known from previous investigations, that of F. nivale remained to be ascertained.2. In wheat, barley, oats and rye, this fungus causes some loss of plants before or after brairding, and it acts as a continuous check on the growth of established plants sown and grown under adverse conditions, whether infection arises from contaminated soil or seed; good growing conditions largely counteract the effects of contamination.3. F. nivale also attacks ears and grain, preventing grain formation or causing discoloration of formed grains; whilst possible thus to reduce the yield and market value, such attacks are rare in the field.4. The chief result arising from contaminated soil or seed in practice is a general reduction in vigour, a condition more likely to be attributed to causes other than the true one.5. Perennial and Italian rye‐grasses on contaminated soils are reduced first in growth; subsequently, the former is largely killed off by the end of the season, but in the field this stage would be reached in the second season.6. F. nivale grows vigorously within the range of normal summer shade temperature, its optimum being 20–21° C.; it grows slowly at 0–1° C, and in its vegetative state withstands winter conditions, as well as exposure to temperatures as low as – 20° C.; it ceases growth, and loses vitality within a few days, at 32–33° C.7. In culture the fungus grows on media of hydrogen‐ion concentration from 2–5 to 13, the optimum being 6–5 to 6–9; its conidia do not germinate in media more acid than pH 5–0 to 5–2. Neither the existence nor the pathogenicity of the fungus is appreciably affected by the acid or alkaline condition of soils within ordinary field ranges.8. Comparative cultural studies of the British and Continental strains of F. nivale show that they differ consistently and significantly in size of conidia, and in form and rate of growth on certain selective media. These morphological and physiological differences are accompanied by difference in pathogenicity, the Continental strain, so far as has been tested, being more virulent toward cereals and less virulent toward grasses than the British strain.The writer tenders thanks to Dr G‐. H. Pethybridge for helpful criticism of this paper.

Gibberella Saubinetii (Mont.) Sacc. on British Cereals: II. Physiological AKD Pathological Studies

Summary G. Saubinetii (Mont.) Sacc., the conidial stage of which is known as Fusarium graminearum Schwabe, produces mature perithecia on natural and artificial substrata, given ample moisture and a uniform temperature of 21° to 22°C. British summer shade temperature does not suffice for this.The minimum temperature for the germination of conidia and ascospores is about 6°C. Between 5° and 10°C. both kinds of spores develop mycelia, and the fungus can infect cereal seedlings. The optimum temperature for vegetative growth of the fungus and the production of mature perithecia is about 24° C.; the maximum temperature for growth is about 37°C.In its vegetative and perithecial stages this fungus can withstand prolonged exposure to a temperature range of — 1° to — 20°C. and in its vegetative stage it persists through the winter in this country.Under storage conditions it retains its vitality for at least two years in its vegetative stage, and for at least one year (probably much longer) in its perithecial stage.Heating to 100°C. for five minutes under dry conditions kills G. Saubinetii on or in diseased grains, but this treatment of seed grain is not a practicable way of controlling the disease. G. Saubinetii causes “seedling blight” and “foot rot” of cereals, but is much less virulent than .F. culmorum and F. avenaceum in this respect. All three fungi attack the ears in a similar way, with similar virulence and with similar results. G. Saubinetii occurs throughout England and in Ireland, but full details of its frequency of occurrence in the British Isles have not yet been obtained.

Highest Recorded Shade Temperature

IN the issue of NATURE for Sept. 6, 1930, at the bottom of page 386, appears an item, “Sept. 13, 1922. Highest Recorded Temperature.”

TEMPERATURE OF PYREX AND PORCELAIN IN SUNLIGHT1

The relative temperatures of Pyrex glass insulators and porcelain insulators in sunlight are determined in three ways. A computation using the radiation and convection heating equations gives a value of 93 °C as a maximum surface temperature of porcelain in sunlight, with an assumed shade temperature of 40°C. In a similar way 46.5° C was determined for the Pyrex insulator. Measurements are given of the rise in temperature under natural conditions of Pyrex and porcelain insulators mounted on pins. Temperature measurements were made by means of thermocouples cemented to the surface of the insulators. Extreme conditions were further obtained by means of tin reflectors. Under such conditions the experiments show that the temperature of the porcelain insulator increases on the average about three and one-half times that of the Pyrex glass insulator.

The Radiation Integrator in Vacuo, an Instrument for the study of Radiant Heat received from the Sun

The “Radiation Integrator in Vacuo” is an instrument designed by a biologist, to assist in the study of solar radiation, as received on the surface of the earth. The principle of the instrument is that a black bulb in vacuo is exposed to the sun's rays; the bulb, which contains alcohol, is connected to a graduated stem maintained at shade temperature; radiant heat from the sun causes alcohol to distil over the bulb into the stem where its volume is measured. In Samoa the shade temperature is practically constant throughout the year, but one believes on theoretical grounds that more radiation is received from the sun between September and March than at the other season, and that the radiation has two maxima, in October and February. This instrument, which has been observed for 12 months, confirms the expectation. The daily mean distillate, the distillate per hour of sunshine (Campbell Stokes) and the mean distillate for the three hours before noon, all show the same seasonal changes.The instrument has been standardized against Gorczynski's pyrheliometer, so that the readings in c.c. of alcohol can be converted into calories. The instrument is not difficult to make or read, and it can be left in the open in all weathers. It integrates its results and requires to be read once a day in Samoa.

The Highest Recorded Shade Temperature

The Highest Recorded Shade Temperature

The highest recorded shade temperature

The highest recorded shade temperature

The domestic mosquitos of Accra

Samples of water containing mosquito larvae are collected at Accra by the Sanitary Inspectors, and are sent regularly to the Laboratory for identification. The number of samples submitted in this way is never very large, and varies considerably from time to time; but, recently, a careful examination has been made of all the specimens received during a complete year, and it is proposed to analyse in this paper the materials thus collected. In 1910–1911 Graham made a similar study of the larvae found in native water-receptacles at Lagos, and it will therefore be interesting to compare our results with those obtained by him.Accra, the capital of the Gold Coast Colony, is situated on the coast a few miles west of the meridian of Greenwich and about 330 miles north of the Equator. The town itself is divided into three portions, Accra proper to the west, Christiansborg where the Governor resides to the east, and the official residential area Victoriaborg between these two. The surrounding country is level for some miles, but the actual site of the town slopes slightly upwards as it recedes from the sea. Accra is a very dry and dusty town, almost completely denuded of vegetation. The rainfall is low ; during the twelve months under consideration, December 1914 to November 1915, 21·75 inches of rain fell. During the same period the maximum shade temperature averaged 85·39°, the minimum 73·83°, and the relative humidity 72·46°. The physical features and climatic conditions of Accra differ therefore greatly from those of Lagos, a low-lying town surrounded by swamps with an average rainfall of about 70 inches.

THE ANALYSIS OF ILKLEY SPA WATER

Modern Ilkley occupies the site of the Brigantian stronghold of Llecan, which subsequently became the Roman station of Olicana. “Ichley Fountaine,” has been in repute for bathing for about two centuries, a small bath-house having been built in 1699* Hearne’s edition of Leland’s Itinerary contains a letter written by Dr. Richardson in 1709 stating, “Ilkley … chiefly famous for a cold well, which has done very remarkable cures in scrofulous cases by bathing, and in drinking of it.” In 1734 Dr. Short wrote, “Ichley Spaw springs out of the middle of a mountain, a Mile high. … The Water is very clear, brisk and sparkling, has no taste, colour nor smell different from the common Water, is of the same weight. Its Basin and Course are of no other Dye than that of a common Spring. … Five pints of this Liquor exhaled left seven Grains of sediment. … Therefore, though this Water is of the greatest Esteem and Repute of any in the North of England, in the King’s Evil and other old Ulcers; yet it derives these Effects neither from its fixt nor volatile Parts, but wholly from the Coldness and Purity of the Element.”† Dr. Rutty in 1757 quotes from another treatise of Short’s specifying the virtues of the “Ichley Water.”† Dr. Adam Hunter’s examination in 1819 gave:— Temperature, of water, 48° F. Temperature in shade, 64° F. Sp. Gr. at 55° F., 1.00015. A wine gallon was found to contain:— | Muriate of Lime | … | … | 6.50 | ||

Note on an entomological store-box suitable for use in the Tropics

The following is a description of a modified and improved form of the store-box described by Mr. H. Maxwell-Lefroy in Parasitology, vol. iv, p. 174 :—In Khartoum, where the shade temperature is sometimes 116° F., boxes of the type in use at Pusa were found to be unsuitable. The tops and bottoms of many of them split, while the paraffin wax became too soft to hold the cork carpet in position. The type of box which I am now using and which is proving very reliable, differs from the Pusa box in two respects. Instead of being made entirely of teak, the top and bottom are of three-ply wood, and the cork carpet instead of being bedded in paraffin wax is held in position by glue. In all other respects it resembles the Pusa box, the cork carpet being enamelled white above and covered with a mixture of 80 per cent. paraffin wax (melting point 136° F.) and 20 per cent. naphthaline, melted and run in when the glue has become firm.

Meteorology in Australia 1

THE Commonwealth Bureau of Meteorology, Australia has now been in existence more than a year, and issued its first Bulletin a few months ago. This is an article on the “Climate and Meteorology of Australia,” and is written by the Commonwealth meteorologist, Mr. H. A. Hunt. It contains some very interesting data with regard to the climate of the various capitals, and indicates that Adelaide is the driest and sunniest, and that Brisbane-is the hottest, capital. The hottest region is in the northern part of West Australia, near the Marble Bar and Nulla-gine goldfields, where the maximum shade temperature often exceeds 100° for days and even weeks continuously.

Meteorological Observations

SEVERAL reports of meteorological observatories have recently been received, and four of them are of noteworthy interest. The report of the observatory department of the National Physical Laboratory for 1906 shows that the value of the instrumental certificates is very generally appreciated, he increase in the number of instruments verified during the year amounted to more than 2900, the total being 29,567. There was a marked increase in the number of marine chronometers submitted to trial, more than 20 per cent, of which failed to pass the test. In the magnetic department the curves were free from any large disturbances. The largest movements of the seismographs occurred on January 31, April 18, and August 17, the dates of the Colombian, Californian, and Chilian earthquakes. The meteorological observations show that shade temperatures exceeding 80° were recorded in each of the four months June-September, the extreme reading being 91°.8 on September 1. Rainfall amounted to 23.68 inches (nearly half an inch below the average for Greenwich for the sixty-five years 1841–1905); the greatest daily fall was 2.36 inches on June 28, and was within half an inch of the total amount for that month.

Hourly Readings of Black Bulb in vacuo at Ben Nevis Observatory

For a few years readings of a Black Bulb in vacuo thermometer formed part of the regular hourly routine work at the Observatory on Ben Nevis during the summer months, and a summary of two years' observations, for 1890 and 1891, is given in this paper. The instrument consists of the usual vacuum chamber, a spherical glass globe about 2½ inches diameter, with inside, centrically, a thermometer whose bulb and an inch or so of stem are coated a dull black. The thermometer is an ordinary, not a maximum Fahrenheit thermometer, and therefore gives the Black Bulb temperature at the instant of reading only. It was exposed on a wooden stand in a horizontal position, with the bulb projecting beyond the frame, and pointing south, about 4 feet above the broken stones which form the hill top, and was read immediately after the shade temperature during daylight hours.

Extremes of Climate in the British Empire

I HAVE just read the note on p. 87 of your issue of November 28 last giving an abstract of the “Summary of the Climate of the British Empire” in Symons' Meteorological Magazine; and I think that even though it is expressly said to be only “so far as it can be represented by reports for eighteen stations,” such a summary is misleading. Thus, Adelaide is given as having the highest shade temperature, absolutely ignoring the fact that Lahore, with a population 50 per cent, more than Adelaide, has a maximum shade temperature for a month or more at a time rarely falling below 116°, and often well over 120°; while in Jacobabad, a much less important place, it is true, but still a garrison town, the maximum shade temperature in June and July is more often over 120° than under it.

Scientific Serials

Symons's Monthly Meteorological Magazine, October.— Meteorological extremes. II. Temperature. Mr. Symons has collected a large amount of useful information upon this subject from all trustworthy sources. For yearly mean temperatures preference is naturally given to Dr. Buchan's isothermic charts published in the Challenger volume, “The Circulation of the Atmosphere.” The highest yearly isotherms are 85°, and these occur only in three localities, the largest covering a portion of Central Africa, bounded on the north by latitude 18° N. Two smaller areas exist, one in Central India and the other in the northern portion of South Australia, respectively in latitude 15° N. and 15° S. The absolute range of the shade temperature in the northern hemisphere, and probably in the world, is 217°.8, depending on the absolute maximum of 127°.4 in Algeria, July 17, 1879, and the absolute minimum of –90°.4 at Verchoiansk, Siberia, January, 15, 1885. The hottest region is on the south-western coast of Persia, where the thermometer has been known not to fall lower than 100°, night or day, for orty consecutive days during July and August, and often to reach 128° in the afternoon. Among the highest shade temperatures we may mention one at night during the Italian occupation of Massowah, when the thermometer is said to have recorded 122°. Temperatures above 120° are occasionally met within India; 121°.5 was recorded at Dera-Ishmail-Khan (lat. 32° N.) in 1882, and 126°.0 at Bhag (lat. 29° N.) in 1859. At Wilcannia on the Darling River, New South Wales, shade temperatures varying from 107° to 129° were recorded on each day from January 1 to 24 in 1896. Among the low temperatures (in addition to the extremes mentioned above) we may quote –63°.1 at Poplar River, North America, in January 1885. During the intense frost in Scotland on December 4, 1879, –16° was reported from Kelsd and –23° from Blackadder, in Berwickshire. The extremes in or near London for 104 years were 97°.1 in July 1881, and 4° in December 1796 and January 1841.

Scientific Serials

Symons's Monthly Meteorological Magazine, September.—Climatological records for the British Empire in 1896. A table is given showing the chief climatological elements at eighteen stations in various parts of the globe, and is accompanied by interesting remarks upon the results. The highest shade temperature, 111°˙2, occurred, as is most frequently the case, at Adelaide, in January. A temperature of 104°˙8 was recorded at Malta, in August, which appears to be unprecedented.

Shade temperature

Quarterly Journal of the Royal Meteorological SocietyVolume 23, Issue 102 p. 69-87 Article Shade temperature Edward Mawley F.R.H.S.,, Edward Mawley F.R.H.S., PRESIDENTSearch for more papers by this author Edward Mawley F.R.H.S.,, Edward Mawley F.R.H.S., PRESIDENTSearch for more papers by this author First published: April 1897 https://doi.org/10.1002/qj.49702310202Citations: 9AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume23, Issue102April 1897Pages 69-87 RelatedInformation

Scientific Serials

Symons's Monthly Meteorological Magazine, March.—Extreme heat in Australia in January 1896. Mr. Russell, Government Astronomer of New South Wales, writes: “We are having a very hot summer…. Those who hold that icebergs cool the weather will have a nut to crack with the icebergs on one hand, and these excessive heats on the other.” On January 13 the temperature in the shade at Sydney rose to 108°˙5. This is the greatest heat recorded there since 1859; the highest previously registered there was 106°˙9 in January 1863. A temperature of 108° was also registered in Melbourne, but this temperature had been exceeded on three occasions: in January 1862, the shade temperature reached 111°˙1; in 1876, 110°˙7, and in the summer of 1882, 110°˙5. In some inland parts of Victoria, even higher temperatures were recorded.—Severe frost in North America. Unprecedently severe weather has been experienced over the Eastern States of America, and in Newfoundland. On February 17 the thermometer registered 39° of frost at New York, a lower reading than has been recorded so late in the year since observations were begun. In the interior of the State of New York a record of 49° below zero was obtained. In Newfoundland the winter is said to be more severe than has been known for forty years. Snow was lying on the ground to a depth of fifteen feet at St. John's. At Fortune Bay the entire failure of the herring fishery has brought the people to the verge of starvation.