<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31420522</termId><termName>alethoscopes</termName><termType>PT</termType><termNote><![CDATA[ Optical devices invented by Carlo Ponti in 1860, and patented in 1861. These were used to view photographic transparencies or prints. It was claimed that stereoscopic relief was obtained from a single photograph, though the stereo effect was due to the nature of an illusion caused by the single viewing lens of the alethoscope. ]]></termNote><termCreatedDate>2026-03-30 20:53:18</termCreatedDate><relation><relationType>UF</relationType><termId>31420523</termId><termName>alethoscope</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31386070</termId><termName>photograph viewing equipment</termName><termType>PT</termType></relation></term>  </Zthes>