An unusual Barothermometer

An unusual instrument, named "Barothermometer", belonging to the collection of Villa Vigoni, on the Como Lake, Italy, is analysed. The instrument is composed of a U-shaped thermoscope and a spirit thermometer. Both instruments have their tubes placed side-by-side on the same frame and use the same scale. It measures the air temperature and the tendency of the barometric pressure to predict weather changes. A study is made to clarify the operating principle and produce the instructions for use. The development of the ideas to which the instrument has been inspired follows a tree starting with the Galileo's thermoscope, the Amontons air thermometer and finally the Adie sympiesometer. The measuring method is typical of the first half of the 19th century, but the construction details in aluminium, the fonts used in the printed instructions and the colour fading suggest that the instrument was built around 1930-40

A Comprehensive study of the microclimate-induced conservation risks in hypogeal sites. The mithraeum of the Baths of Caracalla (Rome)

The peculiar microclimate inside cultural hypogeal sites needs to be carefully investigated. This study presents a methodology that aimed at providing a user-friendly assessment of the frequently occurring hazards in such sites. A Risk Index was specifically defined as the percentage of time for which the hygrothermal values lie in ranges that are considered to be hazardous for conservation. An environmental monitoring campaign that was conducted over the past ten years inside the Mithraeum of the Baths of Caracalla (Rome) allowed for us to study the deterioration before and after a maintenance intervention. The general microclimate assessment and the specific conservation risk assessment were both carried out. The former made it possible to investigate the influence of the outdoor weather conditions on the indoor climate and estimate condensation and evaporation responsible for salts crystallisation/dissolution and bio-colonisation. The latter took hygrothermal conditions that were close to wall surfaces to analyse the data distribution on diagrams with critical curves of deliquescence salts, mould germination, and growth. The intervention mitigated the risk of efflorescence thanks to reduced evaporation, while promoting the risk of bioproliferation due to increased condensation. The Risk Index provided a quantitative measure of the individual risks and their synergism towards a more comprehensive understanding of the microclimate-induced risks

Three centuries of daily precipitation in Padua, Italy, 1713–2018: history, relocations, gaps, homogeneity and raw data

Long instrumental records are fundamental to study climate changes, but their reliability and quality have to be checked before any statistical research. Moreover, when metadata are used to solve some problems, data interpretation may change and require further work to refine the series. A thorough revision of the three-century precipitation series in Padua (1713–2018) shows that the results of previous analyses were affected by serious biases. This paper clarifies key features concerning early instruments, exposure, relocation and observational protocols. The daily analysis pointed out a number of problems, bias, irregular sampling and underestimations that have passed unobserved so far. A comparison with the parallel series of Bologna and Venice made it possible to distinguish bias from the climate signal or to reconstruct missing data. The instrumental threshold was recognized to be fundamental to determine the frequency of precipitation, but less important with respect to its amount. This paper provides a methodological example to test the goodness of long instrumental series, in particular to identify problems related to metadata and observations, which is the preliminary step to perform a sound correction and obtain a reliable series. It also includes the set of original raw data, transformed into modern units

A comparison between different methods to fill gaps in early precipitation series

The aim of this work is to analyse and compare different methodologies to fill gaps in early precipitation series, and to evaluate which time resolution is reachable, i.e. monthly or daily one. The following methods are applied and tested to fill the 1764–1767 gap in the precipitation series of Padua: (1) using a relationship between monthly amounts and frequencies; (2) transforming a daily log with visual observations into numerical values through analysis, classification, and calibration; (3) substituting the missing values with an instrumental record from a nearby, contemporary station in the same climatic area. To apply the second method, the descriptions reported in the Morgagni Logs are grouped in 37 classes and transformed into numerical values, using for calibration the observed amounts in the Poleni record over the 24-year common period. As a third method, the series of Temanza and Pollaroli in Venice is used to fill the gap, and the application of a factor scale based on the ratio Padua/Venice tempted. The results of these three methods are discussed and commented

“A warning from Mars”: effect of microclimate changes at the Specola Museum of Palermo

The Specola Museum is located at the Palermo Astronomical Observatory and preserves most of its material heritage. It is part of the Museum System of the University of Palermo (SiMuA) and its management and conservation are entrusted to the INAF - Astronomical Observatory of Palermo. Among the historical instruments on display, there is a 19th-century painted wooden globe reproducing the surface of Mars. It has been on display in a showcase, inside the Merz Telescope Hall, for about 20 years without undergoing any type of intervention or evident deterioration sign. From 2021, in less than two years, damages of its pictorial layers occurred at a progressive rate. The European Standard EN 15757 explains that hygroscopic materials are highly vulnerable to microclimate changes. The wooden globe was in good conditions after two decades of permanence at the museum, but the recent control and management of the indoor climate was not compatible with the past climate history of the globe to which it has adapted. The speed of the degradation made it evident that the microclimatic conditions of the room changed abruptly. The warning deduced from the Mars globe deterioration was hence easy to decode: there is something wrong with this climate! It is well known that museum microclimate plays a key role in the conservation of the objects on display. It may trigger or aggravate degradation processes of the materials constituting the object exhibited and affect their “life expectancy”. Moreover, each object responses peculiarly to environment variability, depending on its composition and conservation history. When an artifact is composed of different materials, unexpected synergistic effects may develop. Finding appropriate values range of temperature, relative humidity and illuminance and managing them to guarantee the conservation of the entire collection, and at the same time improving the thermal comfort for people working there, is a difficult task. The issue becomes even more challenging in buildings not originally designed for conservation purposes, as the Specola Museum, located in the ancient observatory rooms, built in 1790 on the top of the 12nd-century Royal Palace. An accurate restoration has been made, and conservation measures have been adopted, to stop the serious deteriorating processes affecting the model of Mars but the risk of further deterioration phenomena involving other objects is expected to increase substantially if no actions are taken. This contribution intends to present the results of the preliminary study concerning the thermo-hygrometric records taken in the Merz Telescope Hall over the last two years and propose specific actions to improve its microclimate conditions. References Carotenuto M. R., Randazzo D., Chinnici I., Genua G., Preventive Conservation Projects on LAM Materials at the INAF-Astronomical Observatory of Palermo “G.S. Vaiana”, Bulletin of the AAS, 54(2) (2022) Carotenuto M. R., Chinnici I. et al., Rapporto tecnico INAF 2022 - Il Museo della Specola: progetti per la conservazione, la fruizione, la comunicazione (2018-2020) Camuffo D., Microclimate for cultural heritage. Measurement, Risk Assessment, Conservation, Restoration, and Maintenance of Indoor and Outdoor Monuments, Elsevier, third Edition (2019) Antomarchi C., Pedersoli Jr., Michalski S., Guide to Risk Management, ICCROM (2016) Foderà Serio G., Chinnici I., L'Osservatorio Astronomico di Palermo, Palermo (1997

Aurorae observed by Giuseppe Toaldo in Padua (1766–1797)

Se presenta un registro de las observaciones de auroras hechas por Giuseppe Toaldo y su asistente Vincenzo Chiminello en Padua, Italia, en la segunda mitad del siglo XVIII. Las fuentes históricas consultadas incluyen los manuscritos originales que contienen los registros meteorológicos realizados por esos dos observadores. Se construye un pequeño catálogo con las 148 observaciones aurorales. Las características de estas observaciones son analizadas. La principal característica de este conjunto de datos es que el número anual de observaciones aurorales presenta un pico intenso alrededor de 1779 y una disminución abrupta alrededor de 1790.A record is presented of the auroral observations made by Giuseppe Toaldo and his assistant Vincenzo Chiminello in Padua, Italy, in the second half of the 18th century. The historical sources consulted include the original manuscripts containing the meteorological records made by those two observers. A small catalogue is constructed with the 148 auroral observations. The characteristics of these observations are analysed. The main feature of this data set is that the annual number of auroral observations presents an intense peak at around 1779 and an abrupt decline at around 1790.• Ministerio de Ciencia e Innovación. Proyectos AYA2008-04864/AYA y AYA2014-57556-P • Junta de Extremadura. Ayuda para Grupos de Investigación GR15137 • Universidad de las Fuerzas Armadas of Ecuador (ESPE). Proyecto 2015-PIC-014 • Gobierno de Ecuador. Secretaría de Educación Superior, Ciencia, Tecnología e Innovación. Proyecto PROMETEO, para Fernando Domínguez CastropeerReviewe

CO Observations of the Interacting Galaxy Pair NGC 5394/95

BIMA CO 1-0 observations are presented of the spiral galaxies NGC 5394 and NGC 5395 that have undergone a recent, grazing encounter. In NGC 5394, 80% of the CO emission detected by BIMA is concentrated in the central 800 pc (FWHM) starburst region.In an encounter simulation that reproduces some of the main features of this galaxy pair, a considerable amount of gas in NGC 5394 falls into the central region early in the collision. The observed total gas distribution in the disk of NGC 5394 is lopsided, with more HI, CO, and H-alpha emission coming from the western or southwestern side. The innermost western arm of NGC 5394 is seen in CO and H-alpha emission, but the eastern inner-disk arm, which is very bright in the optical continuum, is not detected in CO or H-alpha emission. From a comparison of the radio continuum, H-alpha, 60 micron, and CO luminosities, we estimate that the average visual extinction of the starburst is 3 - 4 mag and the conversion factor N(H2)/I(CO) in the starburst is a factor of 3 - 4 below the standard value. Comparison of NGC 5394 with two other systems previously studied suggests that in prograde grazing encounters a central starburst may not develop until near the end of the ocular phase. Very little of the CO emission from NGC 5395 found in previous single-dish observations is detected by BIMA.Comment: AAS-Latex, v5.0, 45 pages including embedded .ps figures. AJ, in pres