Browse Items (356 total)

A tachometer (revolution-counter, Tach, rev-counter, RPM gauge) is an instrument measuring the rotation speed of a shaft or disk, as in a motor or other machine. The device usually displays the revolutions per minute (RPM) on a calibrated analogue…

This model shows a geometric surface called a hyperboloid of one sheet. It was used in mathematics and architecture classes. The wires are straight lines. For any point on the surface, there are two straight lines lying entirely on the surface which…

Traktor mit Maschinen Wegeverbesserungen auf derselben Stuecke, die das links stehende Bild aus frueher Zeit wiedergibt.

Blue and white mittens with gray socks.

Digital art featuring a sleeping dog on a purple blanket.

Mixed media art, featuring two anatomical hearts. Created using acrylic, embroidery floss, and pencil.

A sextant is used in nautical navigation measure the angle between two visible objects. The angle, and the time it was measured, can be used to calculate a position line on a nautical or aeronautical chart. A common use of the sextant is to sight the…

Mit philosophischer Gelassenheit blickte die alte Schleiereule auf die Kamera.

Aufgeschreckt, haben sich die jungen Schleiereulen in die äusserste Ecke ihres Horstes zurückgezogen.

Selected pages from the copybook/math journal of the Nelson family. Exhibits the type of elements contained in the journal - math proofs, personal notes, history records, a type of index, geneological records, etc.

Vorgehen italienischer Infanterie im Schutze des Tanks

Zwangloser Unterricht

Many pieces of demonstration equipment must be rotated to show a desired effect. A Rotator is a device with a crank that can rapidly rotate a small horizontal platform about an axis. Other pieces of equipment, like Newton’s Color Wheel, attached to…

Reichsschatzmeister Schwarz spricht in Gegenwart des Führers und Reichskanzlers vom Balkon des neuen Führerhauses zu den Teilnehmern. Im Hintergrund sind die beiden neu errichteten Ehrentempel und das Verwaltungsgebäude der NSDAP, am Koenigsplatz zu…

This was a popular piece of demonstration apparatus, in which the operation of the motor is signaled by a ringing of the bell. The instrument is an inverted revolving electromagnet, with a gearing system added to strike the bell every hundred…

aber für die Zuschauer gibt es nur Stehplätze

Image collage of quilts and baby-themed quilt

Prisms have been standard laboratory equipment since Isaac Newton used one in 1666 to study the nature of the spectrum. Most or all of these prisms were made by Duboscq in Paris.

Flag advertising for the U. S. presidential campaign of John Bell

Mugs and bowls in various colors