Sky & Telescope - December 2018 - 72

u MOVIE NIGHT Aster tried to draw potential new members by scheduling pleasurable
astronomy-themed activities, including movie
screenings. This advertisement invites the public to the view the "most impressive and tragic"
science fiction feature When Worlds Collide.
As the poster suggests, the plot of the movie
revolves around the impending collision of a
great star (Bellus) and Earth. Humans have three
months to plan for their survival. Will anyone
come out of this story alive?

the years. In contrast to the United
States, amateur telescope making
(ATM) never became a mass hobby in
Spain, although a signiﬁcant number of
amateurs like Costas contributed to the
circulation of astronomical knowledge
and supplied information and instruments to those interested in homemade telescopes. A founding member
of the Group for the Dissemination of
Astronomy of Baix Montseny (Grup
Pro Divulgació Astronómica del BaixMontseny, PDA), Costas led the charge
in Spanish ATM.
Costas's early attempts to obtain satisfactory instruments spurred his interest in producing his own telescopes. The
ﬁrst naked-eye observations he made
were soon superseded by observations
using binoculars and homemade instruments - in particular, small but effective refractors made of biconvex lenses
from ordinary glasses and using simple
lenses as oculars. Costas worked with
prisms and lenses, hoping to improve
the performance of his instruments.
The optical material used for such
initiatives was mostly recycled from
other instruments. The most notable of
the instruments, named "Helio," had a 130-cm focal length
and a magniﬁcation of about 60×. Slowly but surely, Costas
became relatively well known in the community of amateur
astronomers for making simple, good-quality, and cheap optical instruments. Indeed, several Catalan amateur astronomers placed orders for instruments.
Costas's work in the postwar years is indicative of the
resurgence of earlier amateur practices and interests, including telescope making. Knowledge about ATM circulated
among amateurs during these years under the inﬂuence of
several initiatives developed by SADEYA and Aster. A good
example of this was the establishment of an Instrument
Commission by the latter, fully operational by the early
1950s, in which issues such as the production of both equatorial mounts and lenses were discussed. This organization was
72

DECE MBE R 2 018 * SK Y & TELESCOPE

inspired by the commission created by
the SAF to deal with the same topic. In
fact, Aster's Instrument Commission
had a productive exchange of information with the commission coordinated
by the noted French telescope maker
Jean Texereau (1919-2014), leading
to the development by the mid-1950s
of a 550-mm-aperture Newtonian
telescope. In addition, Aster edited an
illustrated leaﬂet, entitled The Construction and Operation of an Amateur
Telescope (Construcción y manejo de
un telescopio de aﬁcionado), which
explained how to make cheap telescopes with achromatic objectives.
Several Spanish amateurs attempted
to produce their own mirrors in the
1940s. However, mirror grinding
proved too difﬁcult for most. The
turning point came with Texereau's
1951 book How to Make a Telescope (La
construction du telescope d'amateur). The
publication and circulation of Texereau's work, together with the recovery
and translation into Spanish of several
articles published by Albert G. Ingalls
(1888-1958) in Scientiﬁc American, had
a crucial impact on Spanish amateur
astronomy in the 1950s. Such a boost
for ATM, promoted by astronomical
societies and associations, encouraged
many amateurs to produce their own
low-cost telescopes, notably increasing
the apertures they worked with, mostly
from 60 or 110 mm to 150 mm, 200
mm, and even 300 mm.
A good example of this evolution is the work of Salvador Aguilar
(1913-1988), a mechanical technician
and member of Aster, who had earlier been engaged in the
construction of rudimentary telescopes using glass lenses.
Aguilar devoted part of his small workshop to producing mirrors following Texereau's techniques, as well as to building
complete telescopes. Among his main contributions to ATM
was the development of a vacuum system of aluminization
that helped to overcome (for the ﬁrst time in Spain) problems
related to the chemical silvering of mirrors.
Such interests led SADEYA to organize a workshop in
1957 for teaching interested amateurs how to make reﬂector
telescopes, including the mirrors. The workshop was so successful - with more than 100 attendees - that it was offered
again the following year. Among the attendees of the ﬁrst
workshop organized by SADEYA was the lawyer and amateur
astronomer Josep Maria Alfaras Castañeda (1913-1990). It

AG RUPACIÓN ASTRONÓ MICA ASTER / L A VA NGUA RDIA
ESPA NOL A (FEBRUA RY 23, 1954)

ATM in Spain

Sky & Telescope - December 2018

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