I miei regoli calcolatori / My slide rules

Indice / Table of contents:
Introduzione / Introduction
Unknown manufacturer, Unknown model
Faber Castell, Model 67/54 b
Nestler, Model Multimath Duplex 0292
Neolt, Unknown model
Faber Castell, Model 1/54
Faber Castell, Model 57/89
Aristo, Model Scholar 0903 VS-2
Aristo, Model Scholar 0968 + 1367 + Tab. A
Hono - Rietz, Model 125
Concise, Model 28N
Krugovaya Lineika, Model KL-1
Arithma Addiator

I regoli calcolatori, in passato strumenti di calcolo ampiamente usati nel campo dell'ingegneria, ora in disuso, sono oggetti di rara bellezza e perfezione. Nell'era del digitale, affascinano questi calcolatori analogici, dove il processo di calcolo è calmo e pacato, e la precisione del risultato dipende dall'abilità dell'operatore e dai sapienti e precisi movimenti delle mani. C'è qualcosa di meraviglioso nel riscoprire i principi che danno vita a questi oggetti, forse dimenticati ma mai sorpassati.

Slide rules, once widely used by engineers and now almost obsolete, are objects of uncommon beauty and perfection. In the digital era we can't help being fascinated by these analog calculators, where the calculation process is calm and placid, and the accuracy of the result depends on the operator's skill and on his hands' precise and sage movements. There is something wonderful in rediscovering the principles which give life to these objects, maybe forgotten but never obsolete.

Unknown manufacturer, Unknown model

Front and back of the first slide rule I bought (actually my father bought it to me in 1989). It's got a couple of one-decade scales (lower part of the slider), a couple of two-decade scales (upper part of the slider, using the couples in conjunction it's easy to compute squares and square roots), an inverse scale for the computation of 1/x (drawn in red, in the middle of the slider). The instrument is completed with two single scales: one, at the top edge (a three-decade scale for the computation of cubes and cube roots) and a linear one, at the bottom edge, for the computation of logarithms and exponentials. The instrument is rather cheap in its making; it's composed of wood covered with plastic, the cursor is made of a transparent plastic which is rather weak and subject to cracks.
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A. W. Faber Castell, Model 67/54 b

Front and back of a slide rule made by Castell on behalf of Rohde & Schwarz (well-known german electronics manufacturer), bought at Friedrichshafen's electronics and ham-radio expo, Germany. The slider (wrongly inserted with the rear face up) has scales on both faces: the face shown in the upper photo has the LL1, LL2 and LL3 scales, to be used for the computation of exponentials (useful for phenomena like capacitor charge/discharge), that tell speak about the electronic "inclination" of the rule. By pulling out the slider and inserting it upside-down (by the way, the back face is partially visible in the lower picture) the B, CI and C scales are made available, putting this way together the usual one- and two-decade scales, plus the CI red scale for the inverse calculation. Completano lo strumento tre scale nella parte bassa, utili per il calcolo di funzioni trigonometriche, e due nella parte alta, di cui una a tre decadi per il calcolo dei cubi e una lineare per i logaritmi. Lo strumento possiede anche una riga graduata in centimetri sulla fronte e in pollici sul verso. La fattura dello strumento è abbastanza pregevole. Lo strumento è fornito insieme ad una custodia di pelle di colore blu con il logo dell'azienda Rohde und Schwarz in color argento.
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Nestler, Model Multimath Duplex 0292

Portrayed in the picture is the Multimath Duplex (Nr. 0292), a more than spectacular instrument, manufacture by Nestler. It is here portrayed on a reduced scale if compared with the previous pictures, actually its length is greater than 15 inches. The instrument is composed of 14 scales on each face. On the first face there are four trigonometry scales, six scales (one-, two- and three-decade scales) for powers and inversion, two scales for square roots, one for logarithms plus a final trigonometry one. On the back face, eight scales dedicated to exponentials plus a one-decade couple, a greek pi-translated couple and two inverses.
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Manuale dei regoli calcolatori Nestler, in lingua italiana. Sorry, the manual is available in Italian only. [ cover ] [p. 00, 01] [p. 02, 03] [p. 04, 05] [p. 06, 07] [p. 08, 09] [p. 10, 11] [p. 12, 13] [p. 14, 15] [p. 16, 17] [p. 18, 19] [p. 20, 21] [p. 22, 23] [p. 24, 25] [p. 26, 27] [p. 28, 29] [p. 30, 31] [p. 32, 33] [p. 34, 35] [p. 36, 37] [p. 38, 39] [p. 40]

Neolt, Unknown model

Il regolo qui sopra riportato non è mio, ma appartiene al mio amico Luca Ceresoli, ed è stato costruito a Bergamo. Al momento è l'unico regolo calcolatore di cui sia venuto a conoscenza di cui si sa per certo che sia stato prodotto in Italia.

This rule is not mine, it belongs to my friend Luca Ceresoli, and was built in Bergamo, Italy. To the best of my knowledge, this is the only rule for which I know for sure it was built in Italy.
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A. W. Faber Castell, Model 1/54

A. W. Faber Castell, Model 57/89

Manuale di questo regolo, in tedesco. Manual of this slide rule, in German. [p. 01, 12] [p. 02, 03] [p. 04, 05] [p. 06, 07] [p. 08, 09] [p. 10, 11]

Aristo, Model Scholar 0903 VS-2

Aristo, Model Scholar 0968 + 1367 + Tab. A

Hono - Rietz, Model 125

Concise, Model 28N

Krugovaya Lineika, Model KL-1

Arithma Addiator

Chiude la collezione un piccolo addizionatore digitale (nel senso della definizione) tascabile a cinque cifre. Possiede un piccolo azzeratore da estrarre, mostrato parzialmente estratto nella foto in basso. Lo stilo con cui spostare le scale è purtroppo andato perso. È stato acquistato anch'esso presso la fiera di Friedrichshafen.

We close the collection with a small, digital (in the strict sense of the definition), five-digits pocket adder. It's got a small zeroing pull-out bar, shown partially extracted in the bottom picture. The stylus with which to move the digits got lost. It was bought at Friedrichshafen's expo too.
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