AI & ChatGPT searches , social queriess for CLASS D
Search references for CLASS D. Phrases containing CLASS D
See searches and references containing CLASS D!
Search references for CLASS D. Phrases containing CLASS D
See searches and references containing CLASS D!CLASS D
Topics referred to by the same term
Class D may refer to: Class D (baseball), a defunct class in minor league baseball in North America Class-D amplifier or switching amplifier Class D fire
Class_D
Audio amplifier based on switching
A class-D amplifier, or switching amplifier, is an electronic amplifier in which the amplifying devices (transistors, usually MOSFETs) operate as electronic
Class-D_amplifier
Classification of power amplifier
between class A and class B ( θ = c a 200 {\displaystyle \theta =ca200} °); Class-D and E amplifiers operate their output device in a switching manner; the
Power_amplifier_classes
Class of British steam locomotives
The SECR D class is a class of 4-4-0 tender locomotives designed by Harry Wainwright for the South Eastern and Chatham Railway. The construction of the
SECR_D_class
Topics referred to by the same term
II D-class lifeboat, British lifeboats D-class destroyer (disambiguation), several classes of ships British D-class submarine United States D-class submarine
D_class
Electric multiple unit train
Class D was a type of electric multiple unit train used by the Berlin U-Bahn. After World War II the trains of the Berlin U-Bahn were worn out, making
BVG_Class_D
Serious crime
sub-classes by a Roman numeral; classes range from Class E (encompassing the least severe felonies) through Classes D, C, B, and A–II up to Class A–I
Felony
Hierarchy of professional baseball leagues affiliated with Major League Baseball
for a set price Class C: contracts protected Class D: contracts protected, but any higher class could draft a player for a set price Class E/F: no protection
Minor_League_Baseball
Portion of the atmosphere controlled by a country
generally. Airspace is divided into classes, which dictate what services are provided in different areas. The classes are defined by ICAO, but countries
Airspace
Classification of stars based on spectral properties
subgiants, class V for main-sequence stars, class sd (or VI) for subdwarfs, and class D (or VII) for white dwarfs. The full spectral class for the Sun
Stellar_classification
Class of British steam locomotives
The North Eastern Railway Class D (later London and North Eastern Railway (LNER) Class H1) was a class of 4-4-4T three-cylinder side tank steam locomotive
NER_Class_D
Active fire protection device
U.S. and water, wetting agent, foam, dry chemical (classes ABC and B.C.), and dry powder (class D) types in the rest of the world. Fire extinguishers
Fire_extinguisher
The D class blimp was a patrol airship used by the US Navy in the early 1920s. The D-type blimps were slightly larger than the C-type and had many detail
D-class_blimp
The Danish State Railways (DSB) class D steam locomotive was a 2-6-0 freight steam locomotive developed in co-oporation between the DSB central engineering
DSB_class_D
Class of RNLI inflatable lifeboats
1965–1967 (number range D-59 to D-69) D-class lifeboat (Avon S650), 4 boats built in 1971 (numbers D-200, D-201, D-221, D-222) D-class lifeboat (Zodiac III)
D-class_lifeboat
Class D is a class of airspace in the United States which follows International Civil Aviation Organization (ICAO) air space designation. Class D airspace
List of Class D airports in the United States
List_of_Class_D_airports_in_the_United_States
Early system for organizing the IPv4 address space
classes based on the leading four address bits. Classes A, B, and C provide unicast addresses for networks of three different network sizes. Class D is
Classful_network
Ship class
The C and D class was a group of 14 destroyers built for the Royal Navy in the early 1930s. As in previous years, it was originally intended to order
C_and_D-class_destroyer
The FS Class D.341 is a class of diesel-electric locomotive used in Italy, introduced in the 1950s and still in service. Most of the remaining units are
FS_Class_D.341
Type of British submarines in service before WWI
The D-class submarine was the Royal Navy's first class of submarines capable of operating significantly beyond coastal waters. They were also the first
British_D-class_submarine
Class of hypothetical megastructures
statite components is asymmetrical). A class D stellar engine uses a star’s mass to propel the star. Particular class D stellar engines are the stellar rocket
Stellar_engine
Pair of German cruisers, classified as Panzerschiffe
The D-class cruisers were a pair of German heavy cruisers, classified as panzerschiffe ("armored ships") by the Reichsmarine (Navy of the Realm). The
D-class_cruiser_(Germany)
Topics referred to by the same term
operated two classes of steam locomotives that were classified as the D class: NZR D class (1874) - 33 2-4-0T tank locomotives NZR D class (1929) - 1 experimental
NZR_D_class
Topics referred to by the same term
D-class destroyer may refer to: D-class destroyer (1913), a class of Royal Navy torpedo boat destroyers C and D-class destroyer, a class of Royal Navy
D-class_destroyer
Canadian minor league baseball league
1896–1899, becoming a Class-D league in 1899 and merging into the International League in 1900. In 1905 there was a four-team class D loop known as the Canadian
Canadian_League_(Class_D)
Barry Railway Class D were 0-8-0 steam tender engines of the Barry Railway in South Wales. They were built to a standard Sharp, Stewart and Company design
Barry_Railway_Class_D
The Class D.445 is a class of diesel locomotives used by the Italian Ferrovie dello Stato (FS) railway company and by Trenord. 150 units were built between
FS_Class_D.445
Western Railway (LNWR) Class D was a class of 0-8-0 steam locomotives. They were simple engine rebuilds of earlier Webb Class A three-cylinder compound
LNWR_Class_D
U.S. airspace system classification scheme
non-regulatory. Within these categories exist: controlled (classes A, B, C, D, and E) and uncontrolled (class G) airspace, based on which air traffic control service
Airspace types (United States)
Airspace_types_(United_States)
Class of British 0-6-4T steam locomotives
The LD&ECR Class D was a class of nine 0-6-4T steam locomotives supplied to the Lancashire, Derbyshire and East Coast Railway in 1904 and 1906 by Kitson
LD&ECR_Class_D
Topics referred to by the same term
D-class cruiser can refer to either of the following: Danae-class cruiser, a series of British light cruisers that served during World War II D-class
D-class_cruiser
Computer network protocol
application synchronization. Conformance Class C devices additionally communicate via Profinet IRT. For Conformance Class D (CC-D), Profinet is used via Time-Sensitive
Profinet
NBR Class D by Dugald Drummond
NBR Class D (later LNER Class J34) was a class of 0-6-0 steam locomotive of the North British Railway, often known as the Wee Drummonds. The class was
NBR_D_class_0-6-0
Class of Australian 4-8-0 locomotives
The MRWA D class was a class of 4-8-0 type steam locomotives built by Baldwin Locomotive Works in Philadelphia, USA, for the haulage of goods traffic
MRWA_D_class
Low-floor trams of the Melbourne network
The D-class Melbourne tram is a fleet of low-floor Combino trams that operate on the Melbourne tram network. They were built by Siemens in Uerdingen,
D-class_Melbourne_tram
Type of locomotive
The FS Class D.345 is a class of diesel-electric locomotive used in Italy, introduced in the 1970s and still in service. After the positive experience
FS_Class_D.345
Large and diverse superfamily of cell surface receptors
"Elevated polymorphism and divergence in the class C scavenger receptors of Drosophila melanogaster and D. simulans". Genetics. 169 (4): 2023–34. doi:10
Scavenger receptor (immunology)
Scavenger_receptor_(immunology)
Topics referred to by the same term
D-class tram may refer to: D-class Melbourne tram, built 2002–2004 D-class Melbourne tram (1914) D-class Sydney tram, built 1896–1899 D type Adelaide
D-class_tram
Class of Irish locomotives
The MGWR Class D were 2-4-0 steam locomotives built in batches from 1873 to 1887 for the Midland Great Western Railway (MGWR) of Ireland to a Martin Atock
MGWR_Class_D
The FS Class D.443 is a class of diesel-electric locomotive used in Italy, introduced in the late 1960s and still in service. D.443 was ordered by the
FS_Class_D.443
Class of New Zealand steam locomotives
NZR D class steam tank locomotives operated on New Zealand's national railway network. The first entered service in 1874 all had been withdrawn by the
NZR_D_class_(1874)
The D-class trams are a class of single bogie Californian Combination type trams operated on the Sydney tram network with open cross benches at the ends
D-class_Sydney_tram
Topics referred to by the same term
D-class submarine may refer to: British D-class submarine Spanish D-class submarine United States D-class submarine Japanese Type D submarine, two classes
D-class_submarine
Inflatable D-class lifeboats
The D-class (IB1) lifeboats are inflatable boats serving in the RNLI inshore lifeboat (ILB) fleet as well as a number of Independent Lifeboats around
D-class_lifeboat_(IB1)
The WAGR D class was a single member class of 0-4-0ST tank locomotive operated by the Western Australian Government Railways (WAGR) from 1884 until 1903
WAGR_D_class_(1884)
Large, traditionally rigged sailing vessel
technicalities, but by 2011 there were 4 classes (A, B, C, and D). There are only two size classes, A is over 40 m LOA, and B/C/D are 9.14 m to under 40 m LOA. The
Tall_ship
Class of 40 British 0-6-0T locomotives
The NBR D Class (LNER Class J83) was a class of 0-6-0 tank locomotives designed by Matthew Holmes for short distance freight, station pilot, and heavy
NBR_D_class_0-6-0T
Class of Australian 4-4-0 locomotives
The Commonwealth Railways D class were a class of 4-4-0 construction and shunting locomotives built in 1880 by Beyer, Peacock and Company originally for
Commonwealth_Railways_D_class
Class of Australian 4-6-4T locomotives
The WAGR D class was a class of 4-6-4T tank locomotive operated by the Western Australian Government Railways (WAGR) between 1912 and 1964. In 1911 the
WAGR_D_class
Rollon rolloff ferry
The D-class ferries are a trio of RoRo ferries built by Samsung Heavy Industries between 2003 and 2006 and operated by DFDS Seaways. They were originally
D-class_ferry
Early Garratt locomotive class
The DHR D Class was a one-off 2 ft (610 mm) gauge 0-4-0+0-4-0 Garratt-type articulated steam locomotive used on the Darjeeling Himalayan Railway (DHR)
DHR_D_Class
Topics referred to by the same term
Navy. Delta-class repair ship, a variant of the U.S. Navy MARCOM Type C3-class ship MEKO Delta-class frigate, an alternative name for the MEKO D frigate design
Delta_class
System of categorizing fire
control the fuel supply. Fires involving combustible metals fall under Class D. This especially concerns alkali metals like lithium, potassium and sodium
Fire_classification
1913 class of British destroyers
The D class as they were known from 1913 was a fairly homogeneous group of torpedo boat destroyers (TBDs) built for the Royal Navy in the mid-1890s. They
D-class_destroyer_(1913)
Theorem in stochastic calculus
Doob-Meyer decomposition. In honor of Doob, Meyer used the term "class D" to refer to the class of supermartingales for which his unique decomposition theorem
Doob–Meyer decomposition theorem
Doob–Meyer_decomposition_theorem
Framework which determines use of a property
assigned a letter (from A to D) and a number, creating for example a 'Class A1 Use', a 'Class B3 Use', etc. Each Class is used by the Local Planning
Planning use classes in England and Wales
Planning_use_classes_in_England_and_Wales
Game character aspect
Choose Your D&D Character Class". Kotaku. Retrieved August 19, 2020. Plante, Corey (November 19, 2019). "D&D: Eberron's Artificer class just became canon
Character class (Dungeons & Dragons)
Character_class_(Dungeons_&_Dragons)
Class of enzymes
Carbapenemases were formerly believed to derive only from classes A, B, and D, but a class C carbapenemase has been described. Plasmid-mediated IMP-type
Beta-lactamase
United States Navy submarine class
The United States D-class submarines were a trio of submarines built for the United States Navy in the first decade of the 20th century. All three ships
United States D-class submarine
United_States_D-class_submarine
Soviet Navy nuclear-powered ballistic missile submarine (1960–1991)
the deputy of the chief designer was I.D. Spasskiy. The Hotel design was based on the Project 627 November-class submarine, the first Soviet nuclear submarines
Hotel-class_submarine
Class of British steam locomotives
1887. Class F (compound expansion) and Class F1 (simple expansion) 4-4-0s were developments of T.W. Worsdell's experimental Class D 2-4-0. The Class Ds were
NER_Class_F
Fourth-highest and lowest level of competition in Minor League Baseball
populated areas were classified as Class B, Class C, or Class D. Class A remained the top classification until Class AA was established in 1912, then remained
Single-A
Proposed American battleship class
The Trump-class battleship is a proposed nuclear powered guided-missile warship for the United States Navy, announced by U.S. president Donald Trump in
Trump-class_battleship
Indian Railway freight class electric locomotive
The Indian locomotive class WAG D-9 is a class of 25 kV AC electric locomotives developed by Siemens for Indian Railways. The model name stands for broad
Indian locomotive class WAG D-9
Indian_locomotive_class_WAG_D-9
Motor race in Australia
from Class D to Class C, while the Volkswagens dropped from C to D. Volkswagen would break through for their first class victory this year. Class A was
1962_Armstrong_500
The Chicago and North Western Railway D Class was a class of 92 American 4-4-2 "Atlantic" locomotives. They were built by Schenectady Locomotive Works
Chicago and North Western D class
Chicago_and_North_Western_D_class
2012 survival horror video game
player controls one of the Foundation's many test subjects, known as a Class-D, who must navigate the facility while avoiding numerous threats. The facility’s
SCP_–_Containment_Breach
stations are classified as A, B, C, or D. A (formerly I) — clear-channel stations — 10 kW to 50 kW, 24 hours. Class A stations are only protected within
List of North American broadcast station classes
List_of_North_American_broadcast_station_classes
Dutch electronics company
electronics company known for its class-D audio amplifier modules. These employ a control method called Universal class D (UcD), invented by Bruno Putzeys and
Hypex_Electronics
International standard for electrical and optical cables
850–953 nm range. Class F channel and Category 7 cable are backward compatible with Class D/Category 5e and Class E/Category 6. Class F features even stricter
ISO/IEC_11801
Dungeons & Dragons character class
(also mystic) is a playable character class in most editions of the Dungeons & Dragons fantasy role-playing game. A D&D monk is a fantasy martial artist,
Monk_(Dungeons_&_Dragons)
Inshore lifeboat class of the RNLI
The D-class (EA16) lifeboat is a class of inflatable boat operated since 1987 by the Royal National Lifeboat Institution of the United Kingdom and Ireland
D-class_lifeboat_(EA16)
Class of narrow gauge 2-8-2 locomotives
were rebuilt steam locomotives assembled in the D&RGW Burnham Shops as a near copy of the Rio Grande class K-36. In-house production was chosen to preemptively
Rio_Grande_class_K-37
Class of American aircraft carriers
The Midway class was a class of three United States Navy aircraft carriers. The lead ship, USS Midway, was commissioned in September 1945 and decommissioned
Midway-class_aircraft_carrier
Class of compounds designed to mimic features of peptides
four classes (A – D) where A features the most and D the least similarities. Classes A and B involve peptide-like scaffolds, while classes C and D include
Peptidomimetic
Motor race in Australia
author Bill Tuckey in a Class D Fiat 124 Sport for Scuderia Veloce, the pair finished the race in 18th outright and 9th in class, 11 laps down on the McPhee/Mulholland
1968_Hardie-Ferodo_500
Former railway operator
numbers 3681 and 3682). In comparison to the Class D, the Class E feature larger drive wheels. The Class E was scrapped entirely between 1929 and 1930
Federated Malay States Railways
Federated_Malay_States_Railways
World governing body for air sports
Class A Free Balloons Class B Airships Class C Aeroplanes Class CS Solar-Powered Aeroplanes Class D Gliders & Motorgliders Class E Rotorcraft Class F
Fédération Aéronautique Internationale
Fédération_Aéronautique_Internationale
President of the United States from 1933 to 1945
that young Franklin Roosevelt was self-assured and at ease in the upper class. On the other hand, Eleanor was shy and disliked social life. Initially
Franklin_D._Roosevelt
Senior officer rank of the Royal Navy
and second class. In 1734 the title of commodore was formally approved by an order in council. They were formally separated into first class (those with
Commodore_(Royal_Navy)
Motor race in Australia
which saw the classes released at ten second intervals, with the Class D Roxburgh/Coad Vauxhall starting the race ten seconds before the Class C Russell/Anderson/Loxton
1960_Armstrong_500
Class of Irish locomotives
The MGWR Class D-bogie were first 4-4-0 operated by the Midland Great Western Railway (MGWR) of Ireland. They were rebuilt from MGWR Class D 2-4-0 locomotives
MGWR_Class_D-bogie
Set of problems in computational complexity theory
In computational complexity theory, a complexity class is a set of computational problems "of related resource-based complexity". The two most commonly
Complexity_class
Motor race in Australia
Simca Montlhery and Volkswagen 1200. Class D was for cars with an engine capacity of 1000cc or less. The class featured Ford Anglia, Morris 850, Renault
1961_Armstrong_500
1888 design of steam locomotive
Government Railways placed the first five of its eventual one hundred Class D 4-8-2T steam locomotives in service. The last was delivered in 1899. They
South_African_Class_A_4-8-2T
Axiomatic definition of a class of L-functions
In mathematics, the Selberg class is an axiomatic definition of a class of L-functions. The members of the class are Dirichlet series which obey four axioms
Selberg_class
Motor race in Australia
other three classes, the early leaders each retained their leads throughout the day. Bert Needham and Warren Weldon brought their Class D winning Studebaker
1964_Armstrong_500
Class of British 2-4-0T steam locomotives
The Metropolitan Railway D Class was a group of six 2-4-0T locomotives built for the Metropolitan Railway in 1894-1895 by Sharp, Stewart and Company.
Metropolitan_Railway_D_Class
Academic grading structure in the United Kingdom
honours degrees classified into First Class, Upper Second Class (2:1), Lower Second Class (2:2), and Third Class based on weighted averages of marks. The
British undergraduate degree classification
British_undergraduate_degree_classification
Motor race in Australia
missing out on the Class D win. The new Morris Coopers saw the Mini break out of the entry level class and gave Doug Chivas his first class win, co-driving
1963_Armstrong_500
Honda NSX and Porsche 968 which were expected to be outright threats. Class D : Touring Cars Over 4000cc - featured V8 powered Ford Falcon and Holden
1993_Bathurst_12_Hour
Concept in statistics
c, and d; and disease Z is connected to symptoms a, c, and d. In this context, the LCA would attempt to detect the presence of latent classes (i.e., the
Latent_class_model
Danish company specializing in audio amplification apps
sales company specialising in Class-D amplifiers for audio applications. In 1994 Karsten Nielsen began to write a Ph.D. dissertation "Audio Power Amplifiers
ICEpower
Barsi Light Railway: Class A: 0-8-4T Class B: 4-8-4T Class C: 0-6-0ST Class D: 0-4-0 Class E: Sentinel railcars Class F: 2-8-2 Class G: 4-6-4 Indian Railway
Locomotives_of_India
Technique in the C++ language
if two classes B and C inherit from a class A, and a class D inherits from both B and C, then D will contain two copies of A's member variables: one via
Virtual_inheritance
Class of Royal Navy light cruisers
The Danae or D class consisted of eight light cruisers built for the Royal Navy at the end of World War I which also saw service in World War II. The
Danae-class_cruiser
Class of American narrow gauge 2-8-2 locomotives
the D&SNG's current roster, as the others were converted or are being converted to oil-burning locomotives. Rio Grande class C-19 Rio Grande class K-27
Rio_Grande_class_K-36
Narrow-gauge steam locomotive class
Grande 169 Rio Grande 463 Rio Grande class K-27 Rio Grande class K-28 Rio Grande class K-36 Rio Grande class K-37 D&RGW No. 345 was intentionally damaged
Rio_Grande_class_C-19
2022 South Korean television series
Jae-ho (September 9, 2022). 음악마저 좋은 '약한영웅', OST 발매..'D.P. 음악감독' 프라이머리 프로듀싱 ['Weak Hero Class 1' Busan International Film Festival Official Invitation]
Weak_Hero
Inshore lifeboat class of the RNLI
initially designated as D-class lifeboats, starting a series of boats numbered from D-500, but this was subsequently changed to C-class, to signify the difference
C-class lifeboat (Zodiac Grand Raid IV)
C-class_lifeboat_(Zodiac_Grand_Raid_IV)
CLASS D
CLASS D
Surname or Lastname
English
English : variant of Close 1.German : variant of Kloss.
Girl/Female
Tamil
Glass
Surname or Lastname
North German
North German : topographic name from Middle Low German plas ‘place’, ‘open square’, ‘street’.South German (also Pläss) : from a short form of the medieval personal name Blasius.English : variant of Place 3.
Boy/Male
Australian, Danish, Dutch, Greek, Swedish
People of Victory; Victory of the People
Female
English
English short form of Latin Cassandra, CASS means "she who entangles men."Â
Girl/Female
Indian
Glass
Surname or Lastname
North German variant of Laas 2.Jewish (Ashkenazic)
North German variant of Laas 2.Jewish (Ashkenazic) : unexplained.English : nickname from Middle English lesse, lasse ‘smaller’ (from Old English lǣssa ‘less’), perhaps also used in the sense ‘younger’.
Boy/Male
English Latin Irish Welsh
Wealthy man.
Boy/Male
Arabic
Peace Maker; Brightness; Class
Surname or Lastname
English
English : nickname from Old French, Middle English cras ‘big’, ‘fat’ (Latin crassus).Possibly an altered spelling of German Krass.
Girl/Female
Muslim/Islamic
Glass
Male
German
Short form of German Niclaus, CLAUS means "victor of the people."Â
Surname or Lastname
English
English : from the medieval female personal name Cass, a short form of Cassandra. This was the name (of uncertain, possibly non-Greek, origin) of an ill-fated Trojan prophetess of classical legend, condemned to foretell the future but never be believed; her story was well known and widely popular in medieval England.
Girl/Female
English
Cassandra was a Trojan prophetess, daughter of King Priam. A diminutive of Casirnir, Cassandra,...
Surname or Lastname
English and German
English and German : metonymic occupational name for a glazier or glass blower, from Old English glæs ‘glass’ (akin to Glad, referring originally to the bright shine of the material), Middle High German glas.Irish and Scottish : Anglicized form of the epithet glas ‘gray’, ‘green’, ‘blue’ or any of various Gaelic surnames derived from it.German : altered form of the personal name Klass, a reduced form of Nikolaus (see Nicholas).Jewish (Ashkenazic) : ornamental name from German Glass ‘glass’, or a metonymic occupational name for a glazier or glass blower.
Surname or Lastname
English
English : from the medieval personal name Classe, a short form of Nicholas. See also Clayson.Variant of Klaas or Klass, North German forms of Claus.
Boy/Male
Australian, Dutch, German, Greek
People's Victory
Girl/Female
Indian
Glass
Boy/Male
Greek Latin
People's victory.
Girl/Female
Muslim
Glass
CLASS D
CLASS D
Boy/Male
French German
Guards; guardian.
Surname or Lastname
English
English : variant of Romney.
Boy/Male
Hindu, Indian
Name of the King
Girl/Female
Muslim/Islamic
Flowers
Girl/Female
American, Australian, Christian, Danish, French, German, Greek
Bringer of Good News; Like an Angel
Boy/Male
Australian, Finnish
Sober
Boy/Male
Indian, Punjabi, Sikh
Love of Humanity
Girl/Female
Indian, Sanskrit
Deathless
Boy/Male
Norse
Knot.
Boy/Male
Hindu, Indian, Kannada, Malayalam, Marathi, Tamil, Telugu
Lord Krishna
CLASS D
CLASS D
CLASS D
CLASS D
CLASS D
v. t.
To smooth or polish anything, as leater, by rubbing it with a glass burnisher.
a.
Of the rank or degree below the best highest; inferior; second-rate; as, a second-class house; a second-class passage.
n.
A group of individuals ranked together as possessing common characteristics; as, the different classes of society; the educated class; the lower classes.
a.
Given to viewing one's self in a glass or mirror; finical.
v. t.
An optical glass; a lens; a spyglass; -- in the plural, spectacles; as, a pair of glasses; he wears glasses.
v. t.
A looking-glass; a mirror.
v. t.
A drinking vessel; a tumbler; a goblet; hence, the contents of such a vessel; especially; spirituous liquors; as, he took a glass at dinner.
v. t.
Anything made of glass.
v. t.
Variant of Clasp
n.
One of the sections into which a church or congregation is divided, and which is under the supervision of a class leader.
v. t.
To case in glass.
n.
To divide into classes, as students; to form into, or place in, a class or classes.
v. t.
To shut or fasten together with, or as with, a clasp; to shut or fasten (a clasp, or that which fastens with a clasp).
v. t.
To cover or furnish with glass; to glaze.
n.
To arrange in classes; to classify or refer to some class; as, to class words or passages.
a.
Of the best class; of the highest rank; in the first division; of the best quality; first-rate; as, a first-class telescope.