Milford Haven Research Articles

Measurements of tidal flow variability in Ramsey Sound, Pembrokeshire

The nature of the flow at in-stream tidal energy sites is particularly important for predicting array and device performance, and also for operations and maintenance planning. Previous developers have reported issues such as the choice of vessel, cost of operations, and the limits of operation of deployment vessels. The dynamics of the flow around slack water has been of particular interest at Ramsey Sound in Pembrokeshire (UK) for planning the recovery of an existing turbine, the Tidal Energy Limited ‘Deltastream’.
 This research presents flow characteristics of Ramsey Sound, based on analysis of Acoustic Doppler Current Profiler (ADCP) measurements and tide gauge data from the nearby Standard Port of Milford Haven. The ADCP was located approximately 300 m across the channel, at the northern end of the channel, where the channel width was 1200 m and the mean depth was approximately 33 m. The flow dynamics were examined specifically to look at times potentially suitable for offshore operations Two weeks of data were used in the analysis, spanning a complete spring-neap cycle.
 Results demonstrate that flow velocities exhibited clear asymmetry, with stronger flows on the northerly directed flood tide than on the ebb. There was considerable variation in the measured current speed around the time of the maximum, suggesting large scale bed feature generated turbulence. The flood (northerly) current maximum was approximately in phase with high water at Milford Haven. Cross correlation indicated that the flow generally led the elevation by 20 minutes. In contrast to the expected theory, the current strength at mid-depth was stronger than at the surface on the maximum flood tide. The maximum flow speed in the tide was reasonably predictable from the tide range at Milford. A threshold-based analysis of the ADCP measurements allowed the duration of slow-moving water to be identified for operation planning.
 Operations and planning in light of sound understanding of hydrodynamics at tidal energy sites is critical for future economic success of the tidal energy sector. The results shown here from an ADCP deployment in Ramsey Sound have shown the capability to give useful tools for planning recovery operations.

Combined oil spill modelling and shoreline sensitivity analysis for contingency planning in the Irish Sea

Offshore oil spills often result in severe environmental and socio-economic consequences. This work focuses on a busy, yet poorly studied part of NW Europe, the Irish Sea, to assess the impact of future oil spills on the nearby coast. By integrating numerical models and shoreline sensitivity analyses for two confined areas, Liverpool Bay and Milford Haven, this work acknowledges wind direction and speed as principal controls on the movement of oil under winter/storm conditions and in shallow waters. Ocean currents play a secondary role, but are significant in deeper waters and in low-wind summer conditions. The temporal elements used in the modelling thus stress that when the spill occurs is just as important as where. As a corollary, the fate of spilled oil is determined in this work for distinct scenarios and types. Response strategies are recommended to minimise the impact of future spills on coastal populations.

The Steam Locomotive, the Electric Telegraph And the Demise of Distance: Opportunities and Threats in South Wales, 1845–56

The South Wales Railway was opened between Chepstow in Monmouthshire and Neyland on the Milford Haven estuary between 1850 and 1856, and in combination with the electric telegraph and ancillary railways established a transport and communications network that exercised a profound impact on society and identity in south Wales. By the narrowing of distance through speed, this network brought many urban communities and their nearby districts closer together and was instrumental in transforming the selfimage and identity of south Wales. Conversely, while the network compressed distance, it also forced excluded communities into relative isolation and consequently divided south Wales.

The Co-development of Offshore Wind and Hydrogen in the UK – A Case Study of Milford Haven South Wales

Green hydrogen produced from renewable energy resources can not only contribute to the decarbonisation of different energy sectors, but also serve as a carrier for long-distance delivery of renewable generation, offering a cost-effective way to exploit the renewables far from electrical grids. To facilitate the co-development of offshore wind and hydrogen, the paper develops a modelling framework to dispatch power and hydrogen flows across dedicated offshore wind hydrogen production systems to meet onshore hydrogen demands while keeping similar state of charge levels between multiple systems. Then the hydrogen supply to shore and the system investments and ongoing costs are discounted to their present values to calculate the levelised cost of hydrogen, which is minimised by the particle swarm optimsiation algorithm to suggest the best capacities of hydrogen system components including converters, desalination devices, electrolysers, compressors and storage assets. The proposed modelling framework is tested based on a case study at Milford Haven South Wales which is evaluated to have massive offshore wind resources in the Celtic Sea and comparable demands for hydrogen by 2040. The optimisation results are presented based on the techno-economic input parameters projected for 2030 and 2050 scenarios and discussed alongside the influences of technology advances on the system optimisation and resulting metrics including the levelised costs of hydrogen, net present values and potential levels of green hydrogen supply to Milford Haven.

Characterizing the Marine Energy Test Area (META) in Wales, UK

With lack of convergence on any single wave or tidal technology, test centres have a unique role in the marine renewable energy industry. Test centres facilitate real testing at sea for devices and components at various TRLs (Technology Readiness Level), reducing the time, cost, and risks faced by marine energy developers. META (Marine Energy Test Area) is a £2.7M project managed by Marine Energy Wales (MEW), consisting of eight test areas in the Milford Haven Waterway and surrounding waters (Pembrokeshire, Wales). Although various datasets have been collected from the META test areas over the last decade, and some aspects of these data have been published in various reports, the data has not been gathered together, systematically analysed and critically assessed – the aim of this study. Here, we describe and interpret the various META datasets, including multibeam, ADCP (acoustic Doppler current profiler), and wave buoy data. We report the key parameters of relevance to testing at META, including bathymetry, the nature and magnitude of the tidal currents, turbulence, and wave climates. We make recommendations on future priorities for data collection at META, and discuss the future of the test areas, including expansion into floating wind and other evolving marine energy technologies.

Histopathological survey of putative parasites and pathogens in non-native slipper limpets Crepidula fornicata.

Two populations of the invasive slipper limpet Crepidula fornicata were sampled in Swansea Bay and Milford Haven, Wales, UK, to determine the presence of putative pathogens and parasites known to affect co-located commercially important shellfish (e.g. oysters). A multi-resource screen, including molecular and histological diagnoses, was used to assess 1800 individuals over 12 mo for microparasites, notably haplosporidians, microsporidians and paramyxids. Although initial PCR-based methods suggested the presence of these microparasites, there was no evidence of infection when assessed histologically, or when all PCR amplicons (n = 294) were sequenced. Whole tissue histology of 305 individuals revealed turbellarians in the lumen of the alimentary canal, in addition to unusual cells of unknown origin in the epithelial lining. In total, 6% of C. fornicata screened histologically harboured turbellarians, and approximately 33% contained the abnormal cells-so named due to their altered cytoplasm and condensed chromatin. A small number of limpets (~1%) also had pathologies in the digestive gland including tubule necrosis, haemocytic infiltration and sloughed cells in the tubule lumen. Overall, these data suggest that C. fornicata are not susceptible to substantive infections by microparasites outside of their native range, which may contribute in part to their invasion success.

Invasive slipper limpets (Crepidula fornicata) act like a sink, rather than source, of Vibrio spp.

A large knowledge gap exists regarding the disease profile and pathologic condition of the invasive, slipper limpet Crepidula fornicata. To help address this, we performed a year-long health survey at two sites in South Wales, UK – subtidal Swansea Bay and intertidal Milford Haven. In total, 1,800 limpets were screened systematically for haemolymph bacterial burdens using both general and vibrio-selective growth media (TSA + 2% NaCl and TCBS, respectively), haemolymph (blood) inspection using microscopy, a PCR-based assay targeting Vibrio spp., and multi-tissue histology. Over 99% of haemolymph samples contained cultivable bacterial colony-forming units, and 83% of limpets tested positive for the presence of vibrios via PCR (confirmed via Sanger sequencing). Vibrio presence did not vary greatly between sites, yet a strong seasonal effect was observed with significantly higher bacterial loads during the summer. Binomial logistic regression models revealed larger (older) limpets were more likely to harbour vibrios, and the growth of bacteria on TCBS was a key predictor for PCR-based vibrio detection. Histological assessment of > 340 animals revealed little evidence of inflammation, sepsis or immune reactivity despite the gross bacterial numbers. We contend that slipper limpets are not highly susceptible to bacteriosis at either site, and do not harbour vibrios known to be pathogenic to humans. The lack of susceptibility to local pathogenic bacteria may explain, in part, the invasion success of C. fornicata across this region.

Unravelling the Spatial and Temporal Plasticity of Eelgrass Meadows.

The phenotypic plasticity of seagrasses enables them to adapt to changes in environmental conditions and withstand or recover from disturbance. This plasticity was demonstrated in the large variation recorded throughout a suite of bioindicators measured within Zostera marina meadows around Wales and SW England, United Kingdom. Short-term spatial data were analysed alongside long-term monitoring data to determine which bioindicators best described the status of eelgrass meadows subjected to a range of environmental and anthropogenic drivers. Shoot density, leaf length, leaf nutrients (C:N ratio, %N, %P) including stable isotope of δ13C and δ15N provided insight into the longer-term status of the meadows studied and a good indication of the causes of long-term decline. Meadows ranged from those in the Isles of Scilly with little evidence of impact to those in Littlewick in Milford Haven, Wales that showed the highest levels of impacts of all sites. Bioindicators at Littlewick showed clear warning signs of nutrient loading reflected in the long-term decline in shoot density, and prevalence of wasting disease. This study highlights the need for continuous consistent monitoring and the benefits of using extra tools in the form of shoot nutrient analysis to determine causes of decline.

Agent-based modelling of juvenile eel migration via selective tidal stream transport

Recruitment of temperate eel species Anguilla anguilla, A. rostrata &A. japonica has declined over the last few decades due to human activities, such as overfishing and construction of migratory barriers (e.g. dams, weirs and sluices) and hazardous energy infrastructure (e.g. turbines, intakes and outfalls). Numerical models, substantiated with data from field and laboratory studies, can potentially predict and quantify the relative impacts of such activities, thereby assisting in the sustainable management of eel populations. Here, we present an agent-based model (ABM) of juvenile eel migration up estuaries. The model includes relevant eel behaviours and environmental conditions that, according to the literature, influence upstream migration. Crucially, by assessing the local salinity gradient and relative flow direction, the modelled eels (agents) self-determine whether the tide is flooding or ebbing and orientate themselves for navigation, with no top-down instructions. This allows the agents to decide which particular behaviour to undertake as part of Selective Tidal Stream Transport (STST). The developed ABM is coupled to a hydrodynamic model of the Thames Estuary and the results substantiated by comparison against eel trap data. Combinations of the various STST behaviours are systematically tested and the influence they have on up-estuary migration is assessed in terms of relative energy expenditure. The parameterised model is then used predictively at Milford Haven Waterway to investigate potential impacts on the juvenile eel population due to entrainment in a power plant cooling water intake and outfall. Results from the Thames model case study indicate that including bed anchoring behaviour is essential for achieving a good comparison with the eel trap data and the choice of salinity detection threshold is also important. If daylight avoidance (diel) behaviour is not included, the most energy efficient migration is achieved using just two STST behaviours (ebb tide bed anchoring and upward migration during flood). With diel behaviour included, energy expenditure is greater, but some efficiency is regained by including all of the STST behaviours. For the Milford Haven case study, the model predicted a juvenile eel intake and outfall entrainment rate of 2.0% and 4.7%, respectively. It is concluded that the ABM is a valuable tool for assessing potential impacts on the recruitment of eels (extendable to other species) and could be used to assist in site-selection and low impact design of energy infrastructure in tidal environments.

A Travel Writer Reconsidered: Recovering Mary Morgan’s Mary, the Osier-Peeler

Recently discovered is the singly-extant 1798 quarto chapbook, Mary, the Osier-Peeler, a Simple but True Story, written by Mary Morgan, best known for her 1795 travel narrative, A Tour to Milford Haven, in the Year 1791. The inaccessibility of the osier poem has shaped the scholarly understanding of Morgan as solely a travel writer, disregarding the intertextuality of her published oeuvre and its post-publication circulation. This essay revisits the historiography of Mary Morgan and demonstrates her embeddedness in local networks, coterie relationships with notables such as Bluestocking Elizabeth Montagu, and introduces evidence of a broader, international audience to better contextualize Morgan’s readership and circulation.

Blockchain for energy sharing and trading in distributed prosumer communities

The decentralisation of energy supply and demand can contribute decisively to protecting the environment and climate of the planet by consuming electricity in the proximity of the generation source and avoiding losses in transmission and distribution. Supporting energy transactions with emerging intelligent technologies can advance the development of energy communities and accelerate the integration of renewable sources. Distributed energy solutions play an essential role as they are explicitly designed to produce, store and deliver green energy. Profiting with these benefits is essential, especially in the context of the current debate on stopping climate change. Several technologies such as waste heat recovery with intelligent algorithms can improve the energy distribution and provide significant resource savings. On the other hand, the usage of Blockchain technology in energy markets promises to incentivise the use of renewables and provide a reliable framework to monitor real-time information of energy production and consumption. Blockchain can also enable trading between independent agents and lead to the formation of more secured energy communities.In this paper, we demonstrate how Blockchain can be utilised to support the formation and use of energy communities. We propose a Blockchain-based energy framework as a mean to support energy exchanges in a community of prosumers. We demonstrate how smart contracts can manage energy transactions and enable a more secured trading environment between consumers and producers. We utilise data and models from a real fish processing industrial site in Milford Haven Port, South Wales, based on which we validate our research hypothesis.

Constraining the provenance of the Stonehenge ‘Altar Stone’: Evidence from automated mineralogy and U–Pb zircon age dating

The Altar Stone at Stonehenge is a greenish sandstone thought to be of Late Silurian-Devonian (‘Old Red Sandstone’) age. It is classed as one of the bluestone lithologies which are considered to be exotic to the Salisbury Plain environ, most of which are derived from the Mynydd Preseli, in west Wales. However, no Old Red Sandstone rocks crop out in the Preseli; instead a source in the Lower Old Red Sandstone Cosheston Subgroup at Mill Bay to the south of the Preseli, has been proposed. More recently, on the basis of detailed petrography, a source for the Altar Stone much further to the east, towards the Wales-England border, has been suggested. Quantitative analyses presented here compare mineralogical data from proposed Stonehenge Altar Stone debris with samples from Milford Haven at Mill Bay, as well as with a second sandstone type found at Stonehenge which is Lower Palaeozoic in age. The Altar Stone samples have contrasting modal mineralogies to the other two sandstone types, especially in relation to the percentages of its calcite, kaolinite and barite cements. Further differences between the Altar Stone sandstone and the Cosheston Subgroup sandstone are seen when their contained zircons are compared, showing differing morphologies and U-Pb age dates having contrasting populations. These data confirm that Mill Bay is not the source of the Altar Stone with the abundance of kaolinite in the Altar Stone sample suggesting a source further east, towards the Wales-England border. The disassociation of the Altar Stone and Milford Haven undermines the hypothesis that the bluestones, including the Altar Stone, were transported from west Wales by sea up the Bristol Channel and adds further credence to a totally land-based route, possibly along a natural routeway leading from west Wales to the Severn estuary and beyond. This route may well have been significant in prehistory, raising the possibility that the Altar Stone was added en route to the assemblage of Preseli bluestones taken to Stonehenge around or shortly before 3000 BC. Recent strontium isotope analysis of human and animal bones from Stonehenge, dating to the beginning of its first construction stage around 3000 BC, are consistent with the suggestion of connectivity between this western region of Britain and Salisbury Plain.This study appears to be the first application of quantitative automated mineralogy in the provenancing of archaeological lithic material and highlights the potential value of automated mineralogy in archaeological provenancing investigations, especially when combined with complementary techniques, in the present case zircon age dating.

Federating Smart Cluster Energy Grids for Peer-to-Peer Energy Sharing and Trading

With the rapid growth in clean distributed energy resources involving micro-generation and flexible loads, users can actively manage their own energy and have the capability to enter in a market of energy services as prosumers while reducing their carbon footprint. The coordination between these distributed energy resources is essential in order to ensure fair trading and equality in resource sharing among a community of prosumers. Peer-to-Peer (P2P) networks can provide the underlying mechanisms for supporting such coordination and offer incentives to prosumers to participate in the energy market. In particular, the federation of energy clusters with P2P networks has the potential to unlock access to energy resources and lead to the development of new energy services in a fast-growing sharing energy economy. In this paper, we present the formation and federation of smart energy clusters using P2P networks with a view to decentralise energy markets and enable access and use of clean energy resources. We implement a P2P framework to support the federation of energy clusters and study the interaction of consumers and producers in a market of energy resources and services. We demonstrate how energy exchanges and energy costs in a federation are influenced by the energy demand, the size of energy clusters and energy types. We conduct our modelling and analysis based on a real fish industry case study in Milford Haven, South Wales, as part of the EU H2020 INTERREG piSCES project.

“The Tranquility of a Society of Females”: Mary Morgan’s A Tour to Milford Haven, Elizabeth Montagu, and the Transformative Politics of Female Governance

“The Tranquility of a Society of Females”: Mary Morgan’s A Tour to Milford Haven, Elizabeth Montagu, and the Transformative Politics of Female Governance

Analysis and simulation of smart energy clusters and energy value chain for fish processing industries

The Irish Seafood agency reports that 15% of global energy is consumed by operations related to refrigeration and air conditioning in the fish industry which stresses the importance of integration with clean renewables and adoption of smart energy management solutions. While fish processing industries have high energy costs with continuous refrigeration, air conditioning and ice making processes, there is a real need to analyse and model energy use in fish ports to understand environmental impacts in terms of CO2 emissions while exploring the potential for integrating renewable energy sources.In this paper, we conduct energy modelling and optimization for the Milford Haven fish processing port in South Wales. We explain how a simulation capability can be developed at the fish industry port level and propose a simulation-based optimization strategy to determine optimized schedules for appliances. The results show that energy consumption can be reduced with the use of optimized appliance schedules developed in relation to the total energy demand as well as a wide range of optimization constraints.

Merrison Revolutionised Design after 1970 UK Box Girder Collapses

Engineers have always pushed the boundaries of the possible to create megastructures. In the 1960s, UK innovations were replacing traditional steel girder construction designed to simple BS codes using slide rules. The change was to all welded construction of stiffened box girders, some as cable stayed or suspension bridges. Often old codes were used without reviewing or updating them for the very different scale and proportions of these complex slender structures. The UK Merrison Committee was set up after the fatal 1970 collapses of Milford Haven and West Gate Bridges. It developed Interim Design and Workmanship Rules (IDWR) for the design of steel box girder bridges and the assessment and strengthening of the dozens of deficient UK bridges. Later these comprehensive rules were over simplified into BS5400 and then into EN1993. Today’s engineers contemplating megastructures and those charged with revising EN1993, should re-examine and understand the fundamental basis and source research on which these Codes are based.

Modeling of boilover phenomenon consequences: Computational fluid dynamics (CFD) and empirical correlations

In the present study, empirical correlations were applied to predict the time to boilover and its consequences. Next, a computational fluid dynamics (CFD) model was applied for the simulation of boilover consequences based on the resulting incident radiative heat flux. Empirical correlations, and the Fire Dynamic Simulator (FDS) were compared with a crude oil boilover experiment carried out in a 1m diameter pan (small-scale). FDS predictions were consistent with experimental results. A case study concerning the boilover accident in Milford Haven with a 78m diameter tank (large-scale) was performed with the CFD model and empirical correlations. A comparison of the simulation results and accident data demonstrated that FDS was able to predict the radiation heat flux of the boilover in the target area in agreement with real accident data. The time to boilover correlations gave results in agreement with experimental and real accident data while consequence prediction correlations exaggerated the radiation heat flux and fireball height and diameter. It is concluded that an integrated approach including empirical correlations for the prediction of time to boilover and FDS for the prediction of the radiation heat flux in the target area, provide realistic results for prediction of time to boilover and its consequences.

Tracking Triploid Mortalities of Eastern Oysters Crassostrea virginica in the Virginia Portion of the Chesapeake Bay

Since 2012, aquacultured eastern oysters Crassostrea virginica have been reported by oyster farmers to display mortality approaching 30%, and in some cases 85%, in areas of the lower Chesapeake Bay, VA. Based on accounts from industry, this mortality has typically affected 1-y-old oysters between May and early July, and has tended to occur in triploid oysters, which represent the vast bulk of production in the area. During this period, samples submitted for pathology have not revealed the presence of major pathogens as a cause. In 2015, to gain deeper insight into this mortality and determine whether specific sites, ploidy condition, or genetic lines were affected, oyster seed commercially produced in early 2014 were obtained from four lines, one diploid (2N DEBY) and three triploid (3N DEBY, 3N hANA, and 3N Northern). These lines were deployed in July 2014 at aquaculture farms at five Chesapeake Bay locations: Locklies Creek and Milford Haven on the western shore, and Pungoteague Creek, Nassawadox Creek, and Cherrystone Creek on the Eastern Shore. During this study, mortality was observed to peak in June at most sites, reaching a mean mortality across all tested lines of 17.0% and a cumulative mortality for the study period of 32.0% at Nassawadox Creek, the site most severely affected by mortality that followed the expected early summer mortality pattern. Interval mortality at all sites decreased to under 5% after June, but cumulative levels for the study period reached from 8.8% to 18.6% even at the sites least affected by mortality. This represents a high level of mortality given the documented absence of material involvement by major oyster pathogens such as Hapolosporidium nelsoni and Perkinsus marinus. Infiltration of gill tissues by hemocytes, observed in up to 33% of individuals at Nassawadox Creek coincident with the increase in mortality, was the only pathology observed. Harmful algal blooms were not associated with the mortality, nor were abnormal temperatures or salinities. There was no clear relationship of mortality to oyster genetic heritage, although there was variability in susceptibility among oyster lines and interactions between lines and specific sites. At some locations and in comparison with diploids, triploid oysters appeared to be more susceptible to mortality. Mortality in triploids was coincident with the timing of peak gametogenic development in diploids. Given the lack of involvement by major pathogens and the possible association of mortality with oyster gametogenesis, future work should seek to better understand the suite of environmental stressors potentially impacting cultured oysters in these systems and their interactions with the physiology and energetics of these animals.

J B Wilson

Jack Wilson was born in 1921 in Edinburgh. He went to school at George Watson’s, leaving aged 16, then on to Edinburgh University, where he qualified in 1943. After a...

Merchants and Explorers: Roger Barlow, Sebastian Cabot and Networks of Atlantic Exchange 1500–1560 by Heather Dalton

Reviewed by: Merchants and Explorers: Roger Barlow, Sebastian Cabot and Networks of Atlantic Exchange 1500–1560 by Heather Dalton Michael Bennett Dalton, Heather, Merchants and Explorers: Roger Barlow, Sebastian Cabot and Networks of Atlantic Exchange 1500–1560, Oxford, Oxford University Press, 2016; cloth; pp. 256; R.R.P. £50.00; ISBN 9780199672059. This remarkable study begins with Roger Barlow, hitherto only known, if at all, as the author of A Brief Summe of Geographie, unpublished until the 1930s. In following Barlow's trail, Heather Dalton has opened surprising vistas on early sixteenth-century England, the Atlantic rim, and South America. Impressive archival research in Seville found Barlow among a group of English adventurers involved in business ventures in Spain. In 1526, he participated in a Genoese-financed expedition led by Sebastian Cabot. Its aim was to establish a good route to Moluccas but, heading south, Cabot decided to explore the Rio de la Plata. In his later work, Barlow included observations of the geography, natural history, and the Tupi-Garaní people of the region. He was the first Englishman to describe the humming bird and a cannibal feast. Dalton follows rather than concentrates on Barlow, broadening her focus to discuss Cabot, Barlow's English associates in the Atlantic enterprise, and Barlow's brothers who pursued clerical careers in England. Regarding Cabot, she offers new insights on his puzzling career. In discussing the activities of the Thornes and their Bristol colleagues, she demonstrates the accessibility of Spain to English enterprise through to the 1550s. Her study of Barlow's brothers, John and William, whose careers prospered after the break with Rome, provides a fresh perspective on the English Reformation. [End Page 161] The stories intertwine smoothly and the reframing exercise is always revealing. One revelation is how effectively networks of trust—often familial but surprisingly extended—worked in building capital and knowledge in this uncertain world. A bonus is that Dalton's approach brings into the frame the lives of some remarkable women, generally so fleetingly observed in the records. Catalina de Medrano, the widow of a conquistador and wife of Cabot, did more than mind the shop in Seville during her husbands' absences. She pursued her own interests, consolidated partnerships, and served as a conduit in the exchange of knowledge. On returning to England in 1530, Barlow settled first in Bristol but put down roots in southwest Wales. If he had helped finance the education of his brothers, they now assisted him in making connections and advancing socially. John was Anne Boleyn's chaplain, promoter of Henry VIII's divorce, and dean of Westbury. William became bishop of St David's in 1536. By this time, Roger had leased a substantial property at Slebech, upriver from Milford Haven. Far from the standard cashed-up merchant retiring from the counting-house to a country seat and landed gentility, he had the mindset of a colonist. His estate at Slebech became the centre of an enterprise that drew timber from the hinterland for shipbuilding, participated in illicit as well as licit trade, and profited from anti-piracy operations. Along with his brother, Roger served Thomas Cromwell in establishing the anglicizing and reformist agenda of the government in southwest Wales. Still looking for wider opportunities, Barlow assisted Robert Thorne in a proposal for exploring a northern route to Cathay in the early 1530s. Nicholas Thorne brought a ship from Seville and acted as Cromwell's agent in raising a fleet in 1539. Barlow may have supplied naval stores from Slebech. For some time, he had also been working on a translation of Martín Fernández de Enciso's Suma de Geographia (1519). A novel blend of mathematical and descriptive geography, the Suma was far in advance of work available in English. Barlow included his observations of the Rio de la Plata, expanded the coverage of northern Europe, and customized Enciso's work to reflect English needs. Around 1541, he presented it to Henry VIII, along with a map and a reworked version of the tract on the northern passage. It appears to have been simply filed away. Barlow probably kept in touch with Cabot, who returned to England in 1548. By this...