Search

A reliable and an efficient power system is a necessity for any industrialized society. Governments have to enforce regulations to guarantee that such a power system, in spite of many competing stakeholders, participants, companies, and regulating agencies can be operational. This paper analyzes the present arrangements and the future requirements to be posed on incentives and regulation for ancillary services (AS) for power balancing. The paper proposes companies to assess their own needs for AS. A two-sided market for AS is being described to replace the existing arrangements for secondary control. The proposed solution guarantees a reliable and efficient operation of power systems in a market environment with responsive, reliable, and accountable but also competing prosumers, a large penetration of less-predictable renewables and continent-spanning transmission networks.

To investigate the observed variation in glucose tolerance and insulin secretion in intrauterine growth retarded newborn rats and to explore the mechanism of the variations, Sprague-Dawley pregnant rats were allocated into two groups: a control group and an intrauterine energy restricted group. The intrauterine growth retardation (IUGR) in the rats was induced by 50% calorie restriction in pregnant rats from gestational day 15 until term as compared to the control group. The pancreata of control and IUGR newborn rats were dissected respectively. RT-PCR was used to study the mRNA level related to insulin synthesis and exocytosis. Intraperitoneal glucose tolerance tests were done to study the function of the pancreatic islet. We found that birth weight and pancreas mass of IUGR newborn rats were significantly lower than those of controls. Although no significant differences were observed in mRNA level of insulin and PDX-1, the expression of genes related to insulin exocytosis such as munc13-1, vamp-2, syntaxin1a, rab3a were reduced significantly in IUGR newborn rats. IUGR animals were glucose-intolerant. The observed blood insulin level and insulin secretion response to glucose challenge were both found to be at reduced level in IUGR newborn rats as compared with the normal control group rats. With these findings, we hypothesize that IUGR can induce changes in glucose homeostasis due to, at least in part, a reduced function of insulin exocytosis in newborn rats.

The central question to be examined revolves around the attitudes and awareness of HIV/AIDS among mineworkers at a mine. Semi-standardised questionnaires were used to conduct in-depth interviews on a one-on-one basis. The findings revealed that workers had a great lack of knowledge about AIDS. While some workers had a detailed knowledge of the disease and its prevention, others were either completely ignorant about it or were in denial of its existence. The study serves as a tool and a framework of reference to the mine management on the areas of concern, to put great emphasis on IEC, in order to combat the spread of the disease in the mine. Recommendations are proposed for future research, policy making and practice in the area of HIV/AIDS.These will be in line with the factors influencing mineworkers’ perceptions of the epidemic.

Pelvic malignancies encompass a diverse group of diseases and account for enormous morbidity and mortality worldwide. Given the established role of surgery and with better understanding of the potential synergy between chemotherapy and radiation, an era of combined modality therapy for these malignancies began to emerge in the 1990s. Many single institution and intergroup trials were conducted, establishing the role of combined modality therapy in pelvic malignancies by showing an improved survival, offering organ preservation and limiting surgical complications. However, these benefits accrued at the cost of increased acute toxicities as a result of the combined chemoradiation therapy. Interestingly, limited data suggest no significant increase in late/chronic toxicities, but ongoing and stringent follow-up will be critical to accurately define this issue which is of major interest to all cancer survivors. In the presence of limited data, it would be safe to assume that there is a higher rate of late toxicities given increased early effects lead to increased late effects and perhaps we would have seen these finding if the landmark chemoradiation trials would have collected data on late toxicities. In this chapter, we will review the currently existent literature on acute and late toxicities encountered by combining chemotherapy with radiation in the comprehensive therapy of pelvic malignancies.

Two fog water collection systems (FWCS) have been implemented in South Africa. Both are located in areas where communities experience acute water shortages but which are prone to frequent fog episodes. The first was located at a high elevation site at the Tshanowa Junior Primary (JP) School in the Soutpansberg located in the Northern Province and the other near a small rural community at Lepelfontein along the West Coast. The former represents a mountainous site, while the latter is located on a low level coastal plain. The principal aim of the projects was to implement operational FWCSs to supply the communities with water. During the period 1999 to 2001 the total recorded cloud water yields at the Tshanowa JP School and Lepelfontein water collection sites were in the region of 72 422 and 148 691 1, respectively. This is equivalent to just over 2 1m -2 day -1 at the Tshanowa JP School and 4.6 1 m -2 day -1 at the Lepelfontein site. Despite the relatively low average daily yields recorded, the total water volume collected on a particular day may be considerable. In fact, at both sites the maximum daily yield exceeded 3800 1. Fog deposition accounted for around 25% and 88% of the total water yield measured at the Tshanowa JP School and Lepelfontein sites, respectively. Both experiments indicated that fog water collection holds considerable potential as an alternative water source in the mountainous regions and along the West Coast of South Africa.

A database of the current practice of anterior cruciate ligament (ACL) reconstruction surgery in Great Britain was collated from a postal survey. This survey revealed that clear trends are emerging in the United Kingdom (UK) with regard to ACL reconstruction surgery (such as the type of graft used and timing of surgery) and rehabilitation. Certain issues, however, remain controversial, including bracing and knee range of movement. Clinical outcome measures are consistently used to judge operative success, but few specialists use defined objective measurements such as the IKDC scoring system.

PubMed: 26787795, Background: Transfusion of allogeneic blood influences outcome after surgery. Despite widespread availability of transfusion guidelines, transfusion practices might vary among physicians, departments, hospitals and countries. Our aim was to determine the amount of packed red blood cells (pRBC) and blood products transfused intraoperatively, and to describe factors determining transfusion throughout Europe. Methods: We did a prospective observational cohort study enrolling 5803 patients in 126 European centres that received at least one pRBC unit intraoperatively, during a continuous three month period in 2013. Results: The overall intraoperative transfusion rate was 1.8%; 59% of transfusions were at least partially initiated as a result of a physiological transfusion trigger- mostly because of hypotension (55.4%) and/or tachycardia (30.7%). Haemoglobin (Hb)- based transfusion trigger alone initiated only 8.5% of transfusions. The Hb concentration [mean (sd)] just before transfusion was 8.1 (1.7) g dl-1 and increased to 9.8 (1.8) g dl-1 after transfusion. The mean number of intraoperatively transfused pRBC units was 2.5 (2.7) units (median 2). Conclusions: Although European Society of Anaesthesiology transfusion guidelines are moderately implemented in Europe with respect to Hb threshold for transfusion (7-9 g dl-1), there is still an urgent need for further educational efforts that focus on the number of pRBC units to be transfused at this threshold. © 2016 The Author. Published by Oxford University Press on behalf of the British Journal of Anaesthesia.

Human capital theory postulates that investment in people represents an investment in their productive capacity, whether it be in the form of formal educational training or on-the-job training. Today few, if any, occupations require no investment in human capital. An example is marketing practitioners working in the marketing departments of businesses active in the formal sector of the economy. In this empirical research study, the relationship between the formal training that marketing practitioners receive at higher educational institutions and on-the-job training they receive from businesses employing them, are analysed in terms of their job functions and job specifications. Finally, conclusions regarding this specific relationship are made.

The time evolution of the electric field at a Schottky barrier interface due to above bandgap excitation is directly measured using time-resolved optical second harmonic generation (SHG). The results are found to be in good qualitative agreement with Monte Carlo simulations. Sub-picosecond decay times are observed that are dependent on the excitation powers.

ENGLISH ABSTRACT: e-Procurement is a sound solution for companies to initiate e-business initiatives since it promises several distinct benefits, such as process cost and lead time reduction, improving strategic sourcing of commodities and enabling companies to negotiate better prices. Procurement is a broad term that touches on internal and external aspects of the company, complicating the decision to choose the most suitable e-procurement solution. An evaluation framework is proposed to assist in evaluating the susceptibility of a company’s products to e-procurement and choosing the most suitable e-procurement solution.AFRIKAANSE OPSOMMING: e-Verkryging is ‘n goeie beginpunt vir maatskappye om hulle aan e-besigheid bloot te stel aangesien dit verskeie voordele soos proseskoste en leitydvermindering, verbetering van strategiese aanskaffing van produkte en die vermoë om beter pryse met verskaffers te onderhandel, beloof. Verkryging is ‘n breë term wat heelwat aspekte binne en buite die onderneming behels. Dit bemoeilik die besluit om die mees geskikte e-verkryging-oplossing te kies. ’n Evalueringsraamwerk word voorgestel ter ondersteuning van die evaluering van die ontvanklikheid van ‘n onderneming se produkte vir e-verkryging en die keuse van die mees geskikte e-verkrygingoplossing.

ENGLISH ABSTRACT: Supply planning and traffic flow planning are major activities in the automotive manufacturing environment worldwide. Traditionally, the impact of supply planning strategies on plant traffic is rarely considered. This paper describes the development of a Decision Support System (DSS) that will assist automotive manufacturers to analyse the effect of supply planning decisions on plant traffic during the supply planning phase of their logistics planning process. In essence, this DSS consists of a Supply Medium Decision Support Tool (SMDST) (an interactive MS-Excel model with Visual Basic interfacing) and a traffic flow simulation model tool (using eMPlant simulation software).AFRIKAANSE OPSOMMING: Verskaffingsbeplanning en verkeersvloeibeplanning is belangrike aktiwiteite in die motorvervaardigingsbedryf wêreldwyd. Tradisioneel word die uitwerking van verskaffings-beplanningsstrategië op aanlegverkeer selde in ag geneem. Hierdie artikel beskryf die ontwikkeling van ’n Besluitnemings Ondersteuningstelsel (DSS) wat motorvervaardigers sal ondersteun in die analise van die effek van verskaffingsbeplanningbesluite op aanlegverkeer tydens die verskaffingsbeplanningsfase van hulle logistieke beplanningsproses. Hierdie DSS bestaan hoofsaaklik uit ’n Verskaffings-vervoermiddel Besluitnemingshulpmiddel (SMDST) (’n interaktiewe MS-Excel model met “Visual Basic” koppelling) asook ’n simulasiemodel van verkeersvloei (met eM-Plant simulasiesagteware).

We write patterns, such as dots, lines and crosses, in a strongly turbulent air flow by fusing N2 and O2 molecules to NO, which is then used as a tracer. This photosynthesis is done in the focus of a strong UV laser (ArF excimer ¿ Physik, LPX 150). A while (tens of µs) later, the written patterns are made visible through inducing fluorescence with a second (UV) laser. The deformed and dispersed pattern of NO molecules is photographed in the UV using a fast intensified camera [1]. This technique allows us to create tracer patterns at will, and with sizes comparable to the smallest length scale in turbulence. This would have been very hard using seeded particles, such as in particle tracking velocimetry.

This article concentrates on the South African National Defence Force(SANDF), as a South African public sector department, its acceptance of the Batho Pele principles and the implementation of various organisational performance improvement programmes. However, despite accepting the principles and the programmes, it is uncertain whether the SANDF institutionalised them in order to effect continuous performance improvement.

Objective . This study investigated the influence of carbohydrate versus placebo beverage intake on leukocyte and cortisol responses to 90 minutes of running on a treadmill at 70% VO 2max in women. Subjects . Ten moderately trained women athletes (age: 27.6±3.7 yr; VO 2max : 46.6±2.0ml.kg -1 .min -1 ) from the local athletic club volunteered to participate in the study. Design . In a randomised, single blind, placebo-controlled crossover study, subjects received three beverages during exercise: a placebo ad lib (Pla), 6% glucose (voluntary glucose: VG) and 1 000 ml 6% glucose (forced glucose: FG). Blood samples were analysed for serum glucose ([Gluc]) and cortisol ([Cort]), as well as for total white blood cell (WBC) counts and WBC subpopulations. Results . No difference was observed in the volume of beverage intake during Pla and VG trials. [Gluc] was significantly higher in the VG and FG trials when compared with the Pla trial at 45 and 90 minutes (p Conclusion . We conclude that both voluntary and forced ingestion of 6% glucose solutions prevented a rise in cortisol at the end of a 90-minute period of exercise. Although the effect of the unforced ingestion of 6% glucose was less explicit, both forced and unforced ingestion of 6% glucose had an attenuated effect on WBC counts during exercise. South African Journal for Research in Sport, Physical Education and Recreation Vol. 27(2) 2005: 101-111

This paper investigates the level of importance of pre selected service quality variables of local passengers with regard to the services rendered to them when making use of domestic airlines in South Africa and Italy. This information is relevant for management decision making with regard to maintaining a competitive position in a highly competitive air transport industry. The need for the study resulted from a worldwide tendency of economic downturn and the public caution on air travel, which is caused by the capacity of the airline industry to exceed demand substantially. The aim of this paper is therefore to identify the most important variables that travellers in South Africa and Italy value and expect from a domestic airline service provider. The outcome of the research may offer better understanding with regard to service quality management in the airline industry in developing countries and developed countries and could result in developing competitive strategies based upon quality concepts.

Part 1 Detection and analysis of food spoilage: Quantitative detection and identification methods for microbial spoilage Detection, identification and enumeration methods for spoilage yeasts Detection, identification and enumeration methods for spoilage moulds Modelling microbial spoilage Determining the stability and shelf-life of foods. Part 2 Managing food spoilage: Managing microbial food spoilage: an overview Managing microbial spoilage in the dairy industry Managing microbial spoilage in cereal and baking products Managing microbial spoilage in the meat industry. Part 3 Spoilage yeasts: Zygosaccharomyces and related genera Saccharomyces and related genera Candida and related genera Dekkera/Brettanomyces spp. Part 4 Spoilage moulds: General characteristics of moulds Zygomycetes Penicillium and related genera Aspergillus and related teleomorphs Other types of spoilage moulds. Part 5 Spoilage bacteria: Pseudomonas and related genera Lactic acid bacteria Spore-forming bacteria Enterobacteriaceae Other spoilage bacteria.

Many consider simulation to be a highly specialist activity: it is difficult to undertake and is even more difficult to understand its outcomes. The new version of the business process modeling tool Protos attempts to more closely integrate modeling and simulation facilities into one tool. The assumed benefit is that business professionals may more easily undertake simulation experiments when they are enabled with the same tool to extend their existing process models to carry out simulation experiments. This paper explains how the existing engine of the Petri-net based tool ExSpect is integrated into Protos 7.0. It also shows the extended user interface of Protos and the simulation reports it generates.

We have reviewed the literature on the anatomy of the posteromedial peripheral ligamentous structures of the knee and found differing descriptions. Our aim was to clarify the differing descriptions with a simplified interpretation of the anatomy and its contribution to the stability of the knee. We dissected 20 fresh-frozen cadaver knees and the anatomy was recorded using video and still digital photography. The anatomy was described by dividing the medial collateral ligament (MCL) complex into thirds, from anterior to posterior and into superficial and deep layers. The main passive restraining structures of the posteromedial aspect of the knee were found to be superficial MCL (parallel, longitudinal fibres), the deep MCL and the posteromedial capsule (PMC). In the posterior third, the superficial and deep layers blend. Although there are oblique fibres (capsular condensations) running posterodistally from femur to tibia, no discrete ligament was seen. In extension, the PMC appears to be an important functional unit in restraining tibial internal rotation and valgus. Our aim was to clarify and possibly simplify the anatomy of the posteromedial structures. The information would serve as the basis for future biomechanical studies to investigate the contribution of the posteromedial structures to joint stability.

A widely used polarizer in the IR is the wire-grid polarizer. Wire-grid polarizers with a typical minimal wire spacing of ~0.25 microm perform well in the middle IR and the far IR, but in the near IR the performance deteriorates as the wavelength approaches the wire spacing. A possibility for improving this performance is to put two wire grids in tandem with their transmission axes parallel. Starting with the extended Mueller matrix description for a single wire grid, we present a mathematical treatment of this tandem polarizer showing that performance improves quadratically; e.g., a single polarizer extinction ratio of 100 increases to a tandem extinction of 10,000. The improved performance is also verified experimentally.

Part 1 Risk assessment and management in the food chain: Introduction Detecting pathogens in food Modeling the growth, survival and death of microbial pathogens in foods Risk assessment and pathogen management Emerging foodborne pathogens and the food industry Pathogen control in primary production: meat, dairy and eggs Pathogen control in primary production: crop foods Pathogen control in primary production: fisheries and aquaculture Pathogen control in primary production: bivalve shellfish Hygienic plant design Hygienic equipment design Sanitation Safe process design and operation The effective implementation of HACCP systems in food processing Good practice for food handlers and consumers. Part 2 Bacterial hazards: Preservation principles and technologies: Pathogenic Escherichia coli Salmonella Listeria monocytogenes Campylobacter and Arcobacter Other Gram-negative bacterial pathogens Staphylococcus aureus and other pathogenic Gram positive cocci Pathogenic Clostridium species Pathogenic Bacillus species. Part 3 Other agents of foodborne disease: Hepatitis viruses and emerging viruses Parasites: Cryptosporidium, Giardia, Cyclospora, Entamoeba histolytica, Toxoplasma gondii and pathogenic free-living amoebae (Acanthamoeba spp. and Naegleria fowleri) as foodborne pathogens Foodborne helminth infections Toxigenic fungi Mycobacterium paratuberculosis Transmissible Spongiform Encephalopathy (Prion Disease) Histamine fish poisoning: new information to control a common seafood safety issue Gastroenteritis viruses.

Coherent Rayleigh-Brillouin scattering is a four-wave mixing technique that provides information on various physical properties of the scattering medium in the spectral domain. Being based on density gratings generated by dipole forces, the method requires two pump beams of sufficient spectral width to span the full response bandwidth of the scattering medium. We provide experimental data on the scattered spectrum as a function of the coherence between the two pump beams and derive the corresponding pump beam spectrum. We argue that all experiments on coherent Rayleigh-Brillouin scattering to date, have, in fact, been performed in the incoherent regime and show that orders of magnitude in scattering efficiency are to be expected when the experiments are performed with bandwidth-limited picosecond laser pulses.

In this report, experiences with on-line PD measurements on turbogenerator stator insulation using the VHF PD detection technique are discussed. The discussion is focussed on the care that should be taken with on-line PD detection, regarding the following topics: localization of PD sources, comparison of PD results, and selecting measurement frequencies.

Considerable experience of the treatment of irresectable hepatic colorectal metastases has accumulated over the past three decades. In this review, the rationale for hepatic artery treatment of colorectal metastases to the liver is presented and various access techniques and chemotherapeutic agents for infusion are discussed. Randomized trials of hepatic artery chemotherapy (HAC) are analysed, and the promising results of recent studies combining less toxic and more effective agents are summarized. Continuous infusion pumps provide the most reliable and long-lasting access for HAC. Appropriate surgical techniques and medical management can minimize complications. Although tumour progression is best controlled by HAC, a clear-cut survival advantage has yet to be demonstrated. While hepatic artery infusion chemotherapy cannot yet be recommended outside investigational protocols, the experience gained so far should stimulate further studies.

Techniques for the development of mathematical models in the area of predictive microbiology have greatly improved recently, allowing better and more accurate descriptions of microbial responses to particular environmental conditions, thus enabling predictions of those responses to be made with greater confidence. Recognising the potential value of applying these techniques in the food industry, the Ministry of Agriculture, Fisheries and Food (MAFF) initiated a nationally coordinated five-year programme of research into the growth and survival of microorganisms in foods, with the aim of developing a computerised Predictive Microbiology Database in the UK. This initiative has resulted in the systematic generation of data, through protocols which ensure consistency of methodology, so that data in the database are truly comparable and compatible, and lead to reliable predictive models. The approaches taken by scientists involved in this programme are described and the various stages in the development of mathematical models summarized. It is hoped that this initiative and others being developed in the USA, Australia, Canada and other countries, will encourage a more integrated approach to food safety which will influence all stages of food production and, eventually, result in the development of an International Predictive Microbiology Database.

We investigate coherent Rayleigh–Brillouin spectroscopy as an efficient process to measure the bulk viscosity of gases at gigahertz frequencies. Scattered spectral distributions are measured using a Fizeau spectrometer. We discuss the statistical error due to the fluctuating mode structure of the used pump laser. Experiments were done for both polar and nonpolar gases and the bulk viscosity was obtained from the spectra using the Tenti S6 model. Results are compared to simple classical kinetic models of molecules with internal degrees of freedom. At the extremely high (gigahertz) frequencies of our experiment, most internal vibrational modes remain frozen and the bulk viscosity is dominated by the rotational degrees of freedom. Our measurements show that the molecular dipole moments have unexpectedly little influence on the bulk viscosity at room temperature and moderate pressure.

The effective integration of on‐the‐job development with off‐the‐job training does not happen often, but when it does the effects can be dramatic. To realise this strategy one company, Kingsway, recognised a need to make a major investment in the development of managerial talent. A bold but essential strategic investment in management trainees to counter an earlier lower priority to management development is described. The effective link with a management centre (Sundridge Park) is explored, particularly in relation to securing learning while managing. The power of projects, as a development method and part of this partnership, is described with bottom‐line benefits in relation to achieving task goals and learning goals. It is shown that a partnership between an enlightened company and a progressive management centre can make such goals realistic.

Ocular malignant melanoma, similar to the cutaneous variety, may metastasize to the placenta, almost always in the presence of widespread disease. The prognosis is poor, and there is a 25% risk of spread to the fetus. All women with a history of this disease should be informed of the risks when they are contemplating pregnancy.

Revue des progres techniques et economiques realises sur le procede SASOL de conversion du charbon en combustibles liquides et gazeux

The slurry that appears at the cyclone overflow of a mineral-processing plant is the final product of the crushing and grinding stage, the sole purpose of which is to transform the ore to the optimum size for extraction of the valuable material. It is therefore very important to measure the particle-size distribution in the slurry, whether such measurements are to be used in the implementation of automatic control of the milling process, or simply to indicate how well the milling and classification is being performed. Traditional methods of measurement have involved manual sampling and analysis by, for example, sieving. An on-line technique that has been practised for several years uses the attenuation of ultrasound at two different frequencies for the measurement of a single point on the distribution curve - usually the percentage of material smaller than 75µm. Laser-based instruments can perform multipoint analysis, but their application as on-line meters is limited. The use of ultrasound attenuation might result in measurements that are faster and, because a larger sample can be examined, possiby more accurate and reliable. This paper discusses the problems involved in the on-line measurement of the particle-size distribution in a slurry with particular reference to the ultrasound technique. The technical problems are demonstrated, and mathematical techniques to overcome such problems are examined.

That a change takes place in the hue of the spectrum colours when white is added to them has been noticed, but I am not aware that any measurement of the extent of the change has been made. The need of a quantitative investigation has been forced upon me by the fact that in a research on the colour of fluorescence in various bodies the value of the dominant colours obtained by a photographic method did not correspond exactly with that obtained from visual observations. The photographic results also showed that mixed with the dominant colour of the fluorescence was more or less white light, and it occurred to me that this added white might account for the difference. The colour-measuring apparatus, which has been described in various papers and most recently in the paper “On a Modified Apparatus for the Measurement of Colour,” was employed in the investigation, a slight modification in the method of obtaining the two similar spectra being carried out. In the apparatus described in that paper a portion of the beam of light which had traversed the collimator, the prisms, and the lens which brought the spectrum to a focus was diverted by means of a partially silvered mirror placed in the path of the beam. In that used in the present instance only the lower half of the beam was deflected at right angles to the axis of the beam, and again deflected nearly parallel to its original direction. Both deflections were made by silvered mirrors. The two spectra were of approximately the same intensity. Two colour patches could now be formed side by side on a white surface when slits were inserted in each spectrum. The beam of whie light reflected from the first surface of the first prism could be thrown on either of the patches. In the investigations here given the white was thrown on the right-hand patch which was produced by the spectrum formed the diverted beam.

When the image of a small disc of a spectrum colour is received on the retina of a person possessing normal sense of colour, he observes changes in the hue varying with the portion of the retina on which it falls. On the centre the colour is that of the projected beam, and, as it travels away from the centre, the hue becomes paler as the angular distance becomes greater, and, when a certain angular distance is reached (varying with the intensity of the beam and with its wave-length), the colour vanishes, and the disc appears as white of fair brightness. On this principle the boundaries of colour fields can be mapped. It is evident that, as the disc of light travels across the retina, the composition of the colour changes, and that an increased proportion of “white” is felt as the white boundary of the colour field is approached, whilst the colour itself gradually diminishes.

n/a

n/a

Although it has long been suspected that the amount of light emitted by the corona, as seen at various Solar Eclipses, may vary within comparatively wide limits, no attempts to measure its intensity appear to have been made prior to the Eclipse of December 22, 1870. On that occasion Professor Pickering employed an arrangement constructed on the principle of Bunsen’s photometer. It consisted of a box 9 inches wide, 18 inches high, and 6 feet long, within which a standard candle could be moved backwards and forwards by means of a rod. One end of the box was covered with a piece of thin white paper, on which was a greased spot about half an inch in diameter. The box was adjusted so that the rays from the corona were normal to the plane of the paper, and the lighted candle was moved backwards and forwards within the box until the grease-spot was no longer visible. From a number of observations made during the period of totality of this eclipse, Mr. Waldo O. Ross, acting under Mr. Pickering’s direction, found that the standard candle had to be placed at distances varying from 14·4 to 21 inches from the paper before the visibility of the greased spot was reduced to a minimum. (‘U. S. Coast Survey Reports,’ 1870, p. 172.) The observations were much interrupted by clouds, and are also probably affected by irregularities in the rate of the burning of the candle. The mean of all the readings was 18·5 inches: hence the light of the corona in 1870 was apparently equal to 0·42 of a standard candle at a distance of 1 foot. A precisely similar arrangement was used by Dr. J. C. Smith during the Solar Eclipse of July 29, 1878. Dr. Smith, observing at Virginia City, Montana, U. S., found from eight observations that the candle had to be placed at a distance of 51¼ inches from the screen before the minimum of visibility of the greased spot was obtained.

XXII.—In a previous communication (‘Phil. T rans.,' vol. 178, 1887, A., pp. 251-283) the results of the absorption of sunlight by different thicknesses of atmosphere near sea level were found from measurements of the luminosity of the entire spectrum. The method used was that devised by General Festing and the Author, as detailed in the Bakerian Lecture in 1886. The absorption coefficient for th e different thicknesses of atmosphere at sea level was found by measurements made principally at South Kensington, and these were compared with measures taken at the Eiffel, above Zermatt, at a height of about 8000 feet. It was shown that when the air thickness is represented by x , the minimum intensity for each ray of the spectrum can be fairly represented by I' = Ie- - -017 xa , and the average intensity by I' = Ie -013 xa -4 , being the transmitted and original intensities, and X the wave length.and λ the wave length.

n/a